Document:

<PAGE>

                                                                    EXHIBIT 10.1

                      FIRST AMENDMENT TO CREDIT AGREEMENT
                      -----------------------------------

          THIS FIRST AMENDMENT TO CREDIT AGREEMENT (this "Amendment"), dated
                                                          ---------
effective as of March 23, 2000, is among ENCOMPASS SERVICES CORPORATION, a Texas
corporation (formerly Group Maintenance America Corp., the "Company"), the
                                                            -------
Subsidiaries of the Company listed on the signature pages hereto as Guarantors
(together with each other Person who subsequently becomes a Guarantor,
collectively, the "Guarantors"), the banks and other financial institutions
                   ----------
listed on the signature pages hereto under the caption "Banks" (together with
each other person who becomes a Bank, collectively, the "Banks") CHASE BANK OF
                                                         -----
TEXAS, NATIONAL ASSOCIATION, individually as a Bank and as Syndication Agent,
FIRST UNION NATIONAL BANK, individually as a Bank and as Documentation Agent,
and BANK OF AMERICA, N.A., individually as a Bank ("Bank of America") and as
                                                    ---------------
Administrative Agent for the other Banks (in such capacity, together with any
other Person who becomes the administrative agent, the "Administrative Agent").
                                                        --------------------

          A.   The Company, the Banks, the Syndication Agent, the Documentation
Agent and the Administrative Agent have entered into that certain Credit
Agreement dated as of February 22, 2000 (as amended, restated, or modified from
time to time, the "Credit Agreement").
                   ----------------

          B.   The Company has requested that the Credit Agreement be amended in
certain respects, and the Banks party hereto are willing to comply with such
request subject to the terms and provisions of this Amendment.

          NOW, THEREFORE, BE IT RESOLVED, THAT, in consideration of the premises
herein contained and other good and valuable consideration, the receipt and
sufficiency of which are hereby acknowledged, the parties hereto hereby agree as
follows:

                                   ARTICLE 1

                                  Definitions
                                  -----------

          Section 1.1  Definitions.  Capitalized terms used in this Amendment,
                       -----------
to the extent not otherwise defined herein, shall have the same meanings as in
the Credit Agreement, as amended hereby.

                                   ARTICLE 2

                                  Amendments
                                  ----------

          Section 2.1  Amendments to Section 1.01
                       --------------------------

               (a)  The following definitions appearing in Section 1.01 of the
                                                           ------------
Credit Agreement are hereby amended to read in their entirety as follows:
<PAGE>

          "Loan" and "Loans" means Revolving Loans (including Swingline
Advances), Tranche A Term Loans, and Tranche B Term Loans and, solely for
purposes of Section 2.07(b) hereof, Tranche C Term Loans.

          "Term Loans" means, collectively, Tranche A Term Loans and Tranche B
Term Loans and, solely for purposes of Section 2.07(b) hereof, Tranche C Term
Loans.

               (b)     The following additional definitions are added to Section
1.01 of the Credit Agreement to appear therein in their proper alphabetical
order and to read in their entirety as follows:

          "First Amendment" means the First Amendment to this Agreement dated as
of March 23, 2000.

          "Tranche C Term Loan" shall have the meaning provided in Section
                                                                   -------
7.03(r).
-------

          Section 2.2  Amendments to Section 2.07(b).  Clause (v) of Section
                       -----------------------------   ---------------------
2.07(b) of the Credit Agreement is hereby amended to read in its entirety as
-------
follows:

               (v)     Application of Proceeds of Prepayments. All prepayments
                       --------------------------------------
               pursuant to this Section 2.07, other than pursuant to clauses (i)
                                ------------                         -----------
               and (ii) above, shall be applied to the Term Loans, pro rata with
               --------
               respect to each remaining installment of principal (including the
               final installment due on the Term Loans), until the Term Loans
               are paid in full and thereafter to the Revolving Loans without
               any reduction in the Revolving Loan Commitments. Prepayments made
               pursuant to clause (i) above shall be applied to the Revolving
                           ----------
               Loans without any reduction in the Revolving Loan Commitments.
               Prepayments made pursuant to clause (ii) above shall be applied
                                            -----------
               pro rata to all of the Loans (and pro rata with respect to each
               remaining installment (including the final installment) of the
               Term Loans) with a permanent reduction of the Revolving Loan
               Commitments in the amount of the prepayment applied to the
               Revolving Loans. Anything herein to the contrary notwithstanding,
               so long as any Tranche A Term Loan or Tranche B Term Loan is
               outstanding, any holder of a Tranche C Term Loan shall have the
               right to refuse to be prepaid its portion of any prepayment
               pursuant to this Section 2.07(b). In such event, the prepayment
               refused by such holder of a Tranche C Term Loan shall be
               allocated as provided in this clause (v) to holders of Loans
               other than holders of a Tranche C Term Loan.

          Section 2.3  Amendment to Section 7.03.  Section 7.03 of the Credit
                       -------------------------   ------------
Agreement is hereby amended by deleting the word "and" at the end of clause (p)
thereof, by changing the period at the end of clause (q) thereof to a semi-colon
followed by the word "and," and by inserting thereafter a new clause (r) to read
in its entirety as follows:

               (r)     Up to $200,000,000 in principal amount of additional
          Indebtedness under this Agreement or an independent agreement (secured
          by the Collateral) to constitute a

                                       2
<PAGE>

     new Tranche C Term Loan (herein so called) such loan to be substantially on
     the terms set forth in Exhibit A to the First Amendment) in the event that
     the Company is able to identify existing or additional lenders willing to
     commit to advance such additional amount provided that:
                                              --------
     (i) as of the date of the First Amendment to this Agreement, none of the
     Banks party to the Credit Agreement have agreed to commit to advance any
     such additional amount; (ii) the weighted average life to maturity and
     maximum contractual interest rate of such additional obligations shall not
     materially exceed (or, in the case of maturity, be materially less than)
     those described under Exhibit A to the First Amendment; and (iii) no
     changes to the covenants contained herein will be made without the consent
     of Majority Banks.

     Section 2.4  Amendment to Section 7.04.  Section 7.04 of the Credit
                  -------------------------   ------------
Agreement is hereby amended by deleting the word "and" at the end of clause (g)
thereof, by changing the period at the end of clause (i) thereof to a semicolon
followed by the word "and," and by inserting thereafter a new clause (j) to read
in its entirety as follows:

          (j)     Liens on the Collateral securing the Tranche C Term Loan pari
                                                                           ----
     passu with the Liens created by the Loan Documents (which Liens may be
     -----
     created by amending the Security Documents to treat the Obligations and the
     Tranche C Term Loan equally and ratably as secured obligations thereunder).

                                   ARTICLE 3

                 Ratifications, Representations and Warranties
                 ---------------------------------------------

     Section 3.1  Ratifications.  The terms and provisions set forth in this
                  -------------
Amendment shall modify and supersede all inconsistent terms and provisions set
forth in the Credit Agreement and except as expressly modified and superseded by
this Amendment, the terms and provisions of the Credit Agreement and the other
Loan Documents are ratified and confirmed and shall continue in full force and
effect.  The Company and the Banks agree that the Credit Agreement as amended
hereby and the other Loan Documents shall continue to be legal, valid, binding
and enforceable in accordance with their respective terms, except, in each case,
as such enforceability may be limited by bankruptcy, insolvency, reorganization,
moratorium, fraudulent transfer or other similar laws relating to or affecting
the enforcement of creditors' rights generally, and by general principles of
equity regardless of whether such enforceability is sought in a proceeding in
equity or at law.

     Section 3.2  Representations and Warranties.  The Company hereby represents
                  ------------------------------
and warrants to the Banks that (i) the execution, delivery and performance of
this Amendment and any and all other Loan Documents executed and/or delivered in
connection herewith have been authorized by all requisite action on the part of
the Company and will not violate the certificate or articles of incorporation,
other organizational documents or bylaws of the Company or any Guarantor; (ii)
the representations and warranties contained in the Credit Agreement, as amended
hereby, and any other Loan Document are true and correct in all material
respects on and as of the date hereof as though made on and as of the date
hereof (except to the extent that such

                                       3
<PAGE>

representations and warranties were expressly, in the Credit Agreement, made
only in reference to a specific date); and (iii) no Default or Event of Default
has occurred and is continuing.

                                   ARTICLE 4

                                 Miscellaneous
                                 -------------

     Section 4.1  Conditions to Effectiveness.  This Amendment shall be
                  ---------------------------
effective upon the execution hereof by the Company, Majority Banks and the
Administrative Agent and upon delivery to the Administrative Agent of each of
the following documents:

     (a) Resolutions.  Resolutions of the board of directors or other
         -----------
     appropriate body of the Company and each Subsidiary certified by its
     Secretary or an Assistant Secretary or other analogous officer or
     representative which authorize the execution, delivery and performance by
     such Person of this Amendment and such other Loan Documents to be executed
     in connection herewith to which it is or is to be a party;

     (b) Incumbency Certificate.  A certificate of incumbency certified by the
         ----------------------
     Secretary or an Assistant Secretary or other analogous officer or
     representative of the Company and each Subsidiary certifying as to the name
     of each officer or other representative of such Person (i) who is
     authorized to sign this Amendment or any Loan Documents to which such
     Person is or is to be a party (including any certificates contemplated
     herein), together with specimen signatures of each such officer or other
     representative, and (ii) who will, until replaced by other officers or
     representatives duly authorized for that purpose, act as its representative
     for the purposes of signing documents and giving notices and other
     communications in connection with the Loan Documents and the transactions
     contemplated thereby;

     (c) Articles or Certificates of Incorporation, etc.  Certified copies of
         ----------------------------------------------
     any amendments of or other changes to the articles or certificates of
     incorporation, certificate of formation, certificate of limited
     partnership, partnership agreement or other analogous constitutional
     document of the Company and each Subsidiary since February 22, 2000,
     certified by the Secretary of State or other applicable Governmental
     Authority of the state or other jurisdiction of incorporation or
     organization of such Person and dated as of a current date;

     (d) Bylaws.  Certified copies of any amendments of or other changes to the
         ------
     bylaws or other analogous constitutional document of the Company and each
     Subsidiary since February 22, 2000, certified by the Secretary or an
     Assistant Secretary or other analogous officer or representative of such
     Person;

     (e) Government Certificates.  Certificates of appropriate officials as to
         -----------------------
     the existence and good standing, status or compliance, as applicable, of
     the Company and each Subsidiary, reasonably requested by the Administrative
     Agent, in their respective jurisdictions of incorporation or organization
     and any and all jurisdictions where such

                                       4
<PAGE>

     Person is qualified to do business as a foreign corporation or other
     entity, each such certificate to be dated as of a current date;

     (f) Payment of Fees and Expenses.  The Company shall have paid all fees and
         ----------------------------
     expenses of or incurred by the Administrative Agent and its counsel to the
     extent billed on or before the date hereof and payable pursuant to this
     Amendment;

     (g) No Prohibitions.  No Governmental Requirement shall prohibit the
         ---------------
     consummation of the transactions contemplated by this Amendment or any
     other Loan Document to be delivered in connection herewith, and no order,
     judgment or decree of any Governmental Authority or arbitrator shall, and
     no litigation or other proceeding shall be pending or threatened which
     would, enjoin, prohibit, restrain or otherwise adversely affect the
     consummation of the transactions contemplated by this Amendment or the
     other Loan Documents to be delivered in connection herewith;

     (h) Opinion of Counsel.  Opinion addressed to the Administrative Agent and
         ------------------
     the Banks from Bracewell & Patterson, L.L.P. and the General Counsel to the
     Company, as to such matters as the Administrative Agent may reasonably
     request; and

     (i) Proceedings Satisfactory.  All matters and proceedings taken in
         ------------------------
     connection with this Amendment and the other Loan Documents to be delivered
     in connection herewith shall be reasonably satisfactory to the
     Administrative Agent and its counsel.

Borrower shall deliver, or cause to be delivered, to the Administrative Agent
sufficient counterparts of each agreement, document or instrument to be received
by the Administrative Agent under this Section 4.1 to permit the Administrative
                                       -----------
Agent to distribute a copy of the same to each Lender.

     Section 4.2  Survival of Representations and Warranties.  All
                  ------------------------------------------
representations and warranties made in this Amendment or any other Loan Document
including any Loan Document furnished in connection with this Amendment shall
survive the execution and delivery of this Amendment and the other Loan
Documents, and no investigation by the Banks or the Administrative Agent shall
affect the representations and warranties or the right of the Banks or the
Administrative Agent to rely upon them.

     Section 4.3  Reference to Credit Agreement.  Each of the Loan Documents,
                  -----------------------------
including the Credit Agreement and any and all other agreements, documents, or
instruments now or hereafter executed and delivered pursuant to the terms hereof
or pursuant to the terms of the Credit Agreement as amended hereby, are hereby
amended so that any reference in such Loan Documents to the Credit Agreement
shall mean a reference to the Credit Agreement as amended hereby.

     Section 4.4  Expenses of Agent.  As provided in the Credit Agreement, the
                  -----------------
Company agrees to pay on demand all costs and expenses incurred by the
Administrative Agent in connection with the preparation, negotiation, and
execution of this Amendment and the other Loan Documents executed pursuant
hereto.

                                       5
<PAGE>

     Section 4.5   Severability. Any provision of this Amendment held by a court
                   ------------
of competent jurisdiction to be invalid or unenforceable shall not impair or
invalidate the remainder of this Amendment and the effect thereof shall be
confined to the provision so held to be invalid or unenforceable.

     Section 4.6   Applicable Law.  THIS AMENDMENT SHALL BE GOVERNED BY AND
                   --------------
CONSTRUED IN ACCORDANCE WITH THE LAWS OF THE STATE OF TEXAS AND THE APPLICABLE
LAWS OF THE UNITED STATES OF AMERICA.

     Section 4.7   Successors and Assigns.  This Amendment is binding upon and
                   ----------------------
shall inure to the benefit of the Company, the Banks and the Administrative
Agent and their respective successors and assigns, except that the Company may
not assign or transfer any of its rights or obligations hereunder without the
prior written consent of the Banks.

     Section 4.8   Counterparts.  This Amendment may be executed in one or more
                   ------------
counterparts, and on telecopy counterparts each of which when so executed shall
be deemed to be an original, but all of which when taken together shall
constitute one and the same agreement.

     Section 4.9   Effect of Waiver.  No consent or waiver, express or implied,
                   ----------------
by the Banks to or for any breach of or deviation from any covenant, condition
or duty by the Company or any Guarantor shall be deemed a consent or waiver to
or of any other breach of the same or any other covenant, condition or duty.

     Section 4.10  Headings.  The headings, captions, and arrangements used in
                   --------
this Amendment are for convenience only and shall not affect the interpretation
of this Amendment.

     Section 4.11  ENTIRE AGREEMENT.  THIS AMENDMENT AND ALL OTHER INSTRUMENTS,
                   ----------------
DOCUMENTS AND AGREEMENTS EXECUTED AND DELIVERED IN CONNECTION WITH THIS
AMENDMENT EMBODY THE FINAL, ENTIRE AGREEMENT AMONG THE PARTIES HERETO AND
SUPERSEDE ANY AND ALL PRIOR COMMITMENTS, AGREEMENTS, REPRESENTATIONS AND
UNDERSTANDINGS, WHETHER WRITTEN OR ORAL, RELATING TO THIS AMENDMENT, AND MAY NOT
BE CONTRADICTED OR VARIED BY EVIDENCE OF PRIOR, CONTEMPORANEOUS OR SUBSEQUENT
ORAL AGREEMENTS OR DISCUSSIONS OF THE PARTIES HERETO.  THERE ARE NO ORAL
AGREEMENTS AMONG THE PARTIES HERETO.

     Section 4.12  Reaffirmation of Guaranty.  The undersigned Guarantors of the
                   -------------------------
obligations of the Company to the Banks under the Credit Agreement and the other
Loan Documents each hereby: (i) consents to the execution and delivery of the
foregoing Amendment, (ii) agrees that the Amendment shall not limit or diminish
the obligations of the undersigned under the Credit Agreement as Guarantors,
(iii) reaffirms its obligations under its Guaranty and (iv) agrees that the
Guaranty remains in full force and effect and is hereby ratified and confirmed.

                                       6
<PAGE>

             [The remainder of this page intentionally left blank]

                                       7
<PAGE>

     IN WITNESS WHEREOF, the parties hereto have caused this Agreement to be
executed by their respective officers thereunto duly authorized as of the date
first above written.

                                      THE COMPANY:

                                      ENCOMPASS SERVICES CORPORATION

                                      By: /s/ DARREN B. MILLER
                                         -------------------------------------
                                      Name:  Darren B. Miller
                                      Title: Senior Vice President

                                       8
<PAGE>

GUARANTORS:
----------

ADVENT ELECTRIC CO., INC.
AMERICAN AIR COMPANY, INC.
ATLANTIC ELECTRIC COMPANY, INC.
BARNES IVEY MECHANICAL COMPANY, L.L.C.
B&R ELECTRICAL SERVICES, INC.
BELTLINE MECHANICAL SERVICES, INC.
BRAZOSPORT MANAGEMENT, INC.
BUILDING ONE MECHANICAL SERVICES, INC. (TO BE NAMED ENCOMPASS MECHANICAL
SERVICES, INC.)
BUILDING ONE COMMERCIAL, INC. (F/K/A SPANN BUILDING MAINTENANCE COMPANY, TO BE
NAMED ENCOMPASS COMMERCIAL, INC.)
BUILDING ONE SERVICE SOLUTIONS, INC.
BUYR, INC.
CHAMBERS ELECTRONIC COMMUNICATIONS, INC.
CONSOLIDATED ELECTRICAL GROUP, INC.
CRAMAR ELECTRIC, INC.
C.R. HIPP CONSTRUCTION CO., INC.
D&P JANITORIAL, INC.
DEL-AIR SERVICE COMPANY, INC.
D/FW MECHANICAL SERVICES, INC.
DIRECT ENGINEERED MAINTENANCE, INC.
DIVERSIFIED MANAGEMENT SERVICES, U.S.A., INC.
EDG POWER GROUP, INC.
ELECTRICAL CONTRACTING, INC.
ELECTRICAL DESIGN & CONSTRUCTION, INC.
ENGINEERING DESIGN GROUP, INC.
FACILITYDIRECT.COM, LLC (F/K/A ALLIANCE SUPPLY CO., LLC)
FRED CLARK ELECTRICAL CONTRACTOR, INC.
GAMEWELL MECHANICAL, INC.
GARFIELD-INDECON ELECTRICAL SERVICES, INC.
G.S. FINANCIAL, INC.
G.S. GROUP, INC.
G.S.I. OF CALIFORNIA, INC.
GULF STATES, INC.
HYDRO COOLING, INC.
INTERSTATE BUILDING SERVICES, LLC
IVEY MECHANICAL COMPANY, INC.
IVEY MECHANICAL SERVICES, L.L.C.
K & A MECHANICAL, INC.
THE LEWIS COMPANIES, INC.
LEXINGTON/IVEY MECHANICAL COMPANY, LLC
MCINTOSH MECHANICAL, INC.
MH TECHNOLOGIES, INC.
NATIONAL NETWORK SERVICES, INC.
<PAGE>

OIL CAPITAL ELECTRIC, INC.
OMNI MECHANICAL COMPANY
OMNI MECHANICAL SERVICES, By Omni Mechanical Company
POTTER ELECTRIC CO., INC.
PROCESS DESIGN BUILDERS, LLC
PRO WIRE SECURITY SYSTEMS, INC.
REGENCY ELECTRIC COMPANY, INC.
REGENCY ELECTRIC COMPANY ATLANTA OFFICE
REGENCY ELECTRIC COMPANY CHARLOTTE OFFICE, INC.
REGENCY ELECTRIC COMPANY JACKSONVILLE OFFICE, INC.
REGENCY ELECTRIC COMPANY MEMPHIS OFFICE, INC.
REGENCY ELECTRIC COMPANY ORLANDO OFFICE, INC.
REGENCY ELECTRIC COMPANY PROJECTS GROUP, INC.
REGENCY ELECTRIC COMPANY SOUTH FLORIDA OFFICE, INC.
RIVIERA ELECTRIC CONSTRUCTION CO.
RIVIERA ELECTRIC OF CALIFORNIA, INC.
ROBINSON MECHANICAL COMPANY
SANDERS BROS, INC.
SKC ELECTRIC, INC.
SKCE, INC.
S.L. PAGE CORPORATION
SULLIVAN ELECTRIC, INC.
TAYLOR-HUNT ELECTRIC, INC. (F/K/A TAYLOR ELECTRIC, INC.)
TESTRONICS, INC.
TOWN & COUNTRY ELECTRIC, INC.
TRI-CITY ELECTRICAL CONTRACTORS, INC.
TRI-M BUILDING AUTOMATION SYSTEMS CORP.
TRI-M CORPORATION
TRI-M ELECTRICAL CONSTRUCTION CORP.
TRI-M HOLDING CORP.
TSE ACQUISITION CORP.
TRI-STATE ACQUISITION CORP.
WALKER ENGINEERING, INC.
WALTER C. DAVIS & SON, INCORPORATED
WATSON ELECTRICAL CONSTRUCTION CO.
WILSON ELECTRIC COMPANY, INC.
WAYZATA, INC.
ZWART, INC. (D/B/A MOUNTAIN VIEW ELECTRIC, INC.)

AA ADVANCE AIR, INC.
AA JARL, INC.
A-ABC APPLIANCE, INC.
A-ABC SERVICES, INC.
A-1 MECHANICAL OF LANSING, INC.
AIR CONDITIONING ENGINEERS, INC.
AIR CONDITIONING, PLUMBING & HEATING SERVICE CO., INC.
AIRCON ENERGY INCORPORATED

                                    Page 2
<PAGE>

AIR SYSTEMS, INC.
AIRTRON, INC.
AIRTRON OF CENTRAL FLORIDA, INC.
ALL SERVICE ELECTRIC, INC.
ARKANSAS MECHANICAL SERVICES, INC.
ATLANTIC INDUSTRIAL CONSTRUCTORS, INC.
CALLAHAN ROACH PRODUCTS & PUBLICATIONS, INC.
CARDINAL CONTRACTING CORPORATION
CENTRAL AIR CONDITIONING CONTRACTORS, INC.
CENTRAL CAROLINA AIR CONDITIONING COMPANY
CHAPEL ELECTRIC CO.
CHARLIE CRAWFORD, INC.
CLARK CONVERSE ELECTRIC SERVICE, INC.
COLONIAL AIR CONDITIONING COMPANY
COMMERCIAL AIR HOLDING COMPANY
COMMERCIAL AIR, POWER & CABLE, INC.
CONTINENTAL ELECTRICAL CONSTRUCTION CO.
COSTA AND RIHL, INC.
COSTA & RIHL PLUMBING, INC.
COSTNER BROTHERS, INC.
DIVCO, INC.
DYNALINK CORPORATION
ELECTRICAL ASSOCIATES OF DALLAS, INC.
EVANS SERVICES, INC.
THE FARFIELD COMPANY
FERGUSON ELECTRIC CORPORATION
GENTZLER ELECTRICAL CONTRACTORS, INC.
GILBERT MECHANICAL CONTRACTORS, INC.
GROUPMAC FACILITY SERVICES, INC. (TO BE NAMED ENCOMPASS FACILITY SERVICES, INC.)
GROUPMAC HOLDING CORP. (TO BE NAMED ENCOMPASS HOLDING CORP.), By Airtron, Inc.
     and Paul E. Smith Co., Inc.
GROUPMAC INDIANA, L.L.C. (TO BE NAMED ENCOMPASS INDIANA, L.L.C.)
GROUPMAC MARYLAND CORP. (TO BE NAMED ENCOMPASS MARYLAND CORP.)
GROUPMAC TEXAS L.P. (TO BE NAMED ENCOMPASS TEXAS L.P.), By GroupMAC Holding
  Corp.
HPS PLUMBING SERVICES, INC.
HALLMARK AIR CONDITIONING, INC.
HUNGERFORD MECHANICAL CORPORATION
J.D. STEWARD AIR CONDITIONING, INC.
K & N PLUMBING, HEATING AND AIR CONDITIONING, INC.
LANEY'S, INC.
LINFORD SERVICE CO.
L.T. MECHANICAL, INC.
MACDONALD-MILLER CO., INC.
MACDONALD-MILLER INDUSTRIES, INC.
MACDONALD-MILLER OF OREGON, INC.
MACDONALD-MILLER SERVICE, INC.
MASTERS, INC.

                                    Page 3
<PAGE>

MECHANICAL INTERIORS, INC.
MECHANICAL SERVICES OF ORLANDO, INC.
MERRITT ISLAND AIR & HEAT, INC.
NEW CONSTRUCTION AIR CONDITIONING, INC.
NORON, INC.
PACIFIC RIM MECHANICAL CONTRACTORS, INC.
PAUL E. SMITH CO., INC.
PHOENIX ELECTRIC COMPANY
RAY AND CLAUDE GOODWIN, INC.
RELIABLE MECHANICAL, INC.
ROMANOFF ELECTRIC CORP.
SEQUOYAH CORPORATION
SIBLEY SERVICES, INCORPORATED
SNYDER MECHANICAL
SOUTHEAST MECHANICAL SERVICE, INC.
STATEWIDE HEATING & AIR CONDITIONING, INC.
STEPHEN C. POMEROY, INC.
STERLING AIR CONDITIONING, INC.
SUN PLUMBING, INC.
TEAM MECHANICAL, INC.
TOWER ELECTRIC COMPANY
TRINITY CONTRACTORS, INC.
UNITED ACQUISITION CORP.
VALLEY WIDE PLUMBING AND HEATING, INC.
VAN'S COMFORTEMP AIR CONDITIONING, INC.
VANTAGE MECHANICAL CONTRACTORS, INC.
VERMONT MECHANICAL, INC.
WADE'S HEATING & COOLING, INC.
WIEGOLD & SONS, INC.
WILLIS REFRIGERATION, AIR CONDITIONING & HEATING, INC.
YALE INCORPORATED

By:    /s/ DARREN B. MILLER
       --------------------
Name:  Darren B. Miller
Title: Vice President
       Acting on Behalf of Each of the Above

GROUPMAC MANAGEMENT CO. (to be named Encompass Management Co.)

By:    /s/ DARREN B. MILLER
       --------------------
Name:  Darren B. Miller
Title: Executive Vice President

                                    Page 4
<PAGE>

                                    ADMINISTRATIVE AGENT/BANK:

                                    BANK OF AMERICA, N.A.
                                    as Administrative Agent and Individually, as
                                    a Bank

                                    By:    /s/ RICHARD L. NICHOLS, JR.
                                           ---------------------------------
                                    Name:  Richard L. Nichols, Jr.
                                    Title: Managing Director

                                    Page 5
<PAGE>

                                    SYNDICATION-AGENT/BANK:

                                    CHASE BANK OF TEXAS,
                                    NATIONAL ASSOCIATION
                                    as Syndication Agent and
                                    Individually, as a Bank

                                    By:    /s/ JAMES R. DOLPHIN
                                           -----------------------------
                                    Name:  James R. Dolphin
                                    Title: Senior Vice President

                                    Page 6
<PAGE>

                                    DOCUMENTATION AGENT/BANK:

                                    FIRST UNION NATIONAL BANK
                                    as Documentation Agent and
                                    Individually, as a Bank

                                    By:    /s/  DAVID C. HAUGLID
                                           -----------------------------
                                    Name:  David C. Hauglid
                                    Title: Vice President

                                    Page 7
<PAGE>

                              BANKS:

                              ABN-AMRO BANK NV

                              By:    /s/ LAURIE C. TUZO
                                     -------------------------------
                              Name:  Laurie C. Tuzo
                              Title: Senior Vice President

                              By:    /s/ ERIC R. HOLLINGSWORTH
                                     -------------------------
                              Name:  Eric R. Hollingsworth
                              Title: Vice President

                                    Page 8
<PAGE>

                                    BANK AUSTRIA CREDITANSTALT
                                    CORPORATE FINANCE, INC.

                                    By:    /s/ STEPHEN W. HIPP
                                           --------------------------
                                    Name:  Stephen W. Hipp
                                    Title: Senior Associate

                                    By:    /s/ JOHN G. TAYLOR
                                           ---------------------------
                                    Name:  John G. Taylor
                                    Title: Vice President

                                    Page 9
<PAGE>

                                   THE GOVERNOR AND COMPANY OF
                                   THE BANK OF IRELAND

                                   By:    /s/ BRENDAN MCLOUGHLIN
                                          -------------------------------
                                   Name:  Brendan McLoughlin
                                   Title: Manager

                                   By:    /s/ MARTINA MAHER
                                          -------------------------------
                                   Name:  Martina Maher
                                   Title: Authorised Signatory

                                    Page 10
<PAGE>

                                    THE BANK OF NOVA SCOTIA

                                    By: /s/ M. D. SMITH
                                        ---------------
                                    Name:  M. D. Smith
                                    Title: Agent Operations

                                    Page 11
<PAGE>

                                    BANK ONE, N.A.

                                    By: /s/ GREG SMOTHERS
                                        -----------------
                                    Name:  Greg Smothers
                                    Title: Vice President

                                    Page 12

<PAGE>

                                    BANKBOSTON, N.A.

                                    By:    _________________
                                    Name:  _________________
                                    Title: _________________

                                    Page 13
<PAGE>

                                    BANKERS TRUST COMPANY

                                    By:    __________________
                                    Name:  __________________
                                    Title: __________________

                                    Page 14

<PAGE>

                                    CITICORP USA, INC.

                                    By: /s/ MARK R. FLOYD
                                        -----------------
                                    Name:  Mark R. Floyd
                                    Title: Attorney in Fact

                                    Page 15
<PAGE>

                                    COMERICA BANK

                                    By: /s/ MARK B. GROVER
                                        ------------------
                                    Name:  Mark B. Grover
                                    Title: First Vice President

                                    Page 16
<PAGE>

                                    MANAGING AGENT/LENDER:

                                    CREDIT LYONNAIS,
                                    New York Branch

                                    By:  /s/ PHILLIPPE SOUSTRA
                                         ---------------------
                                    Name:  Phillippe Soustra
                                    Title: Senior Vice President

                                    Page 17

<PAGE>

                                    GMAC COMMERCIAL CREDIT LLC

                                    By:    ________________________
                                    Name:  ________________________
                                    Title: ________________________

                                    By:    ________________________
                                    Name:  ________________________
                                    Title: ________________________

                                    Page 18
<PAGE>

                                    MERCANTILE BANK
                                    NATIONAL ASSOCIATION

                                    By: /s/ GREGORY L. DRYDEN
                                        ---------------------
                                    Name:  Gregory L. Dryden
                                    Title: Vice President

                                    Page 19
<PAGE>

                                    THE MITSUBISHI TRUST
                                    AND BANKING CORPORATION

                                    By:    ________________________
                                    Name:  ________________________
                                    Title: ________________________

                                    Page 20
<PAGE>

                                    NATIONAL CITY BANK
                                    OF KENTUCKY

                                    By: /s/ TODD W. ETHINGTON
                                        ---------------------
                                    Name:  Todd W. Ethington
                                    Title: Vice President

                                    Page 21
<PAGE>

                                    PARIBAS

                                    By:    ______________________________
                                    Name:  ______________________________
                                    Title: ______________________________

                                    By:    ______________________________
                                    Name:  ______________________________
                                    Title: ______________________________

                                    Page 22
<PAGE>

                                    SOVEREIGN BANK

                                    By:    ______________________________
                                    Name:  ______________________________
                                    Title: ______________________________

                                    Page 23
<PAGE>

                                       THE SUMITOMO TRUST & BANKING CO., LTD.,
                                       NEW YORK BRANCH

                                       By:    ______________________________
                                       Name:  ______________________________
                                       Title: ______________________________

                                    Page 24
<PAGE>

                                    UNION BANK OF CALIFORNIA, N.A.

                                    By:  /s/ J. SCOTT JESSUP
                                         -------------------
                                    Name:  J. Scott Jessup
                                    Title:  Vice President

                                    Page 25<PAGE>

                                                                    EXHIBIT 10.2

                     SECOND AMENDMENT TO CREDIT AGREEMENT
                     ------------------------------------

     THIS SECOND AMENDMENT TO CREDIT AGREEMENT (this "Amendment"), dated
                                                      ---------
effective as of May 10, 2000, is among ENCOMPASS SERVICES CORPORATION, a Texas
corporation (formerly Group Maintenance America Corp., the "Company"), the
                                                            -------
Subsidiaries of the Company listed on the signature pages hereto as Guarantors
(together with each other Person who subsequently becomes a Guarantor,
collectively, the "Guarantors"), the banks and other financial institutions
                   ----------
listed on the signature pages hereto under the caption "Banks" (together with
each other person who becomes a Bank, collectively, the "Banks") CHASE BANK OF
                                                         -----
TEXAS, NATIONAL ASSOCIATION, individually as a Bank and as Syndication Agent,
FIRST UNION NATIONAL BANK, individually as a Bank and as Documentation Agent,
and BANK OF AMERICA, N.A., individually as a Bank ("Bank of America") and as
                                                    ---------------
Administrative Agent for the other Banks (in such capacity, together with any
other Person who becomes the administrative agent, the "Administrative Agent").
                                                        --------------------

     A.   The Company, the Banks, the Syndication Agent, the Documentation Agent
and the Administrative Agent have entered into that certain Credit Agreement
dated as of February 22, 2000 (as amended by the First Amendment (herein so
called) to Credit Agreement dated as of March 23, 2000, and as further amended,
restated, or modified from time to time, the "Credit Agreement").
                                              ----------------

     B.   The First Amendment permits the Company to secure Tranche C Term Loans
with Liens on the Collateral pari passu with the Liens created by the Loan
                             ---- -----
Documents in the event that the Company was able to identify existing or
additional lenders willing to commit to advance additional amounts subject to
the limitations of the First Amendment.

     C.   The Company has received such commitments from certain of the Banks
party hereto, identified opposite each such Bank's name on its signature page to
this Amendment as making a "Tranche C Term Loan Commitment," to provide
$100,000,000 of Tranche C Term Loans.

     D.   The Company has requested that the Credit Agreement be amended to
provide for such Tranche C Term Loans and additional Tranche C Term Loans up to
an aggregate not to exceed $200,000,000, and the Banks party hereto are willing
to comply with such request subject to the terms and provisions of this
Amendment.

     NOW, THEREFORE, BE IT RESOLVED, THAT, in consideration of the premises
herein contained and other good and valuable consideration, the receipt and
sufficiency of which are hereby acknowledged, the parties hereto hereby agree as
follows:

                                     Page 1
<PAGE>

                                   ARTICLE 1

                                  Definitions
                                  -----------

     Section 1.1  Definitions.  Capitalized terms used in this Amendment, to the
                  -----------
extent not otherwise defined herein, shall have the same meanings as in the
Credit Agreement, as amended hereby.

                                   ARTICLE 2

                                  Amendments
                                  ----------

     Section 2.1  Amendments to Section 1.01
                  --------------------------

          (a) The following definitions appearing in Section 1.01 of the Credit
                                                     ------------
Agreement are hereby amended to read in their entirety as follows:

     "Advance" means (i) an advance, pursuant to a Notice of Advance, comprised
of a single Type of Loan from all the Banks with commitments to make such Loans
(or resulting from a conversion or conversions on the same date having, in the
case of Eurodollar Rate Advances, the same Interest Period (except as otherwise
provided in this Agreement)), made by all of the Banks with commitments to make
such Loans concurrently to the Company, or (ii) a Swingline Advance from Bank of
America or any successor swingline lender approved by the Company and the
Administrative Agent.

     "Bank" means the institutions signatory to the Credit Agreement, the First
Amendment or the Second Amendment, and each other institution that becomes party
hereto pursuant to this Agreement.

     "Commitment" and "Commitments" means the obligation of each of the Banks to
enter into and perform this Agreement, to make available the Loans to the
Company in the amounts shown on the signature page of each Bank hereto (or on
the signature pages to the Second Amendment in the case of Tranche C Term Loan
Commitments) and all other duties and obligations of each of the Banks hereunder
and shall include, without limitation, such Bank's Revolving Loan Commitment,
its Tranche A Term Loan Commitment, its Tranche B Term Loan Commitment and its
Tranche C Term Loan Commitment, as applicable.

     "Eligible Assignee" means (a) any Bank; (b) an Affiliate of a Bank or any
fund that invests in bank loans and is managed by an investment advisor to a
Bank; (c) a commercial bank organized under the laws of the United States, or
any state thereof, and having total assets in excess of $1,000,000,000; (d) a
commercial bank organized under the laws of any other country which is a member
of the Organization for Economic Cooperation and Development or any successor
organization, or a political subdivision of any such country, and having total
assets in excess of $1,000,000,000; provided that such bank is acting through a
branch or agency located in the country in which it is organized or another
country which is also a member of the

                                     Page 2
<PAGE>

Organization for Economic Cooperation and Development or any successor
organization; (e) the central bank of any country which is a member of the
Organization for Economic Cooperation and Development or any successor
organization; and (f) any other bank or similar financial institution approved
by the Administrative Agent.

     "Loan" and "Loans" mean Revolving Loans (including Swingline Advances),
Tranche A Term Loans, Tranche B Term Loans and Tranche C Term Loans.

     "Margin" means: (a) with respect to Revolving Loans (including Swingline
Advances) and to Alternate Base Rate Advances, Eurodollar Rate Advances, or
Commitment Fees, as applicable, the percentage determined in accordance with the
following table:

<TABLE>
<CAPTION>
     ----------------------------------------------------------------------------------------------------------
                                                     Equal to        Equal to       Equal to
                                                    or greater     or greater      or greater
                                                       than            than           than
             Funded Debt/            Equal to      2.75 to 1.00    2.00 to 1.00   1.50 to 1.00
              Pro Forma             or greater         and             and             and
              ---------                than         less than       less than       less than      Less than
            EBITDA Ratio           3.50 to 1.00    3.50 to 1.00    2.75 to 1.00   2.00 to 1.00   1.50 to 1.00
            ------------           ------------    ------------    ------------   ------------   ------------
     ===========================================================================================================
      <S>                         <C>             <C>             <C>             <C>            <C>
      Alternate Base
      Rate Margin                     .50%            .25%              0%             0%             0%
     -----------------------------------------------------------------------------------------------------------

      Eurodollar Margin              2.00%           1.75%           1.50%          1.25%          1.00%
     -----------------------------------------------------------------------------------------------------------

      Commitment Fee                 .375%           .375%           .375%           .25%           .25%
     -----------------------------------------------------------------------------------------------------------
</TABLE>

(b) with respect to Tranche A Term Loans and Tranche B Term Loans and to
Alternate Base Rate Advances, Eurodollar Rate Advances, or Commitment Fees (for
the Tranche A Term Loan Commitment only), as applicable, the percentage
determined in accordance with the following table:

<TABLE>
<CAPTION>
     --------------------------------------------------------------------------------------------
                                                     Equal to        Equal to
                                                    or greater     or greater
                                                       than            than
             Funded Debt/            Equal to      2.75 to 1.00    2.00 to 1.00
              Pro Forma             or greater         and             and
              ---------                than         less than       less than        Less than
            EBITDA Ratio           3.50 to 1.00    3.50 to 1.00    2.75 to 1.00    1.50 to 1.00
            ------------           ------------    ------------    ------------    ------------
     ============================================================================================
     <S>                           <C>             <C>             <C>              <C>
      Alternate Base
      Rate Margin                        1.0%            .75%            .50%           0.25%
     --------------------------------------------------------------------------------------------

      Eurodollar Margin                 2.50%           2.25%           2.00%           1.75%
     --------------------------------------------------------------------------------------------

      Commitment Fee                     .50%            .50%            .50%            .50%
     --------------------------------------------------------------------------------------------
</TABLE>

(c) with respect to Tranche C Term Loans and to Alternate Base Rate Advances
(for the Tranche C Term Loans only) 1.75%, and with respect to Tranche C Term
Loans and to Eurodollar Advances (for the Tranche C Term Loans only) 3.25%;

                                     Page 3
<PAGE>

provided that: (i) for six months after the Effective Date the Margin for
Revolving Loans (including Swingline Advances) shall be 0% or greater for
Alternate Base Rate Advances, 1.50% or greater for Eurodollar Rate Advances and
0.375% for the Commitment Fee; and (ii) for twelve months after the Effective
Date, the Margin for Tranche A Term Loans and Tranche B Term Loans shall be
0.50% or greater for Alternate Base Rate Advances, 2.0% or greater for
Eurodollar Rate Advances and 0.50% for Commitment Fees.

          If sufficient information does not exist to calculate the applicable
Margin, Eurodollar Rate Advances shall not be available to the Company and the
applicable Margin for Alternate Base Rate Advances shall be deemed to be 0.50%
for Revolving Loans, 1.00% for Tranche A Term Loans and Tranche B Term Loans and
1.75% for Tranche C Term Loans.

     "Note" and "Notes" mean the Revolving Notes, the Swingline Note, the
Tranche A Term Notes, the Tranche B Term Notes and the Tranche C Term Notes.

     "Preferred Stock" means preferred Capital Stock of the Company designated
as such by a certificate of designation in existence and delivered to the
Administrative Agent on the Execution Date and additional preferred Capital
Stock the designations for which (a) provide for no mandatory redemption on or
prior to the later of the Term Loan Maturity Date or the Tranche C Term Loan
Maturity Date and (b) provide that no cash dividends are required or permitted
at any time that a Default or an Event of Default exists under this Agreement or
would result from the payment of such cash dividend.

     "Qualified High Yield Offerings" means one or more issuances on or before
the first anniversary of the Effective Date of subordinated, unsecured debt
securities by the Company and/or one or more of its Subsidiaries (which may be
guaranteed by the Company and any of its Subsidiaries on a subordinated basis)
in an aggregate principal amount not to exceed $300,000,000 at any one time
outstanding (a) with a maturity date after the later of the Term Loan Maturity
Date or the Tranche C Term Loan Maturity Date and (b) with an average life to
maturity greater than that of the Term Loans (as of the date of each such
Qualified High Yield Offering).

     "Term Loans" means, collectively, Tranche A Term Loans, Tranche B Term
Loans and Tranche C Term Loans.

     "Total Commitment" means the aggregate Commitments of all Banks totaling a
maximum of $900,000,000 for all Banks; provided that such total maximum amount
                                       --------
may be increased up to $1,000,000,000 as provided in Section 2.01(e).
                                                     ---------------

     "Tranche C Term Loan" shall have the meaning provided in Section 2.01(d).
                                                              ---------------

          (b) The following additional definitions are added to Section 1.01 of
                                                                ------------
the Credit Agreement to appear therein in their proper alphabetical order and to
read in their entirety as follows:

                                     Page 4
<PAGE>

     "Second Amendment" means the Second Amendment to this Agreement dated as of
May 10, 2000.

     "Second Amendment Effective Date" means the date on which all conditions to
the effectiveness of the Second Amendment set forth in Section 4.1 of the Second
                                                       -----------
Amendment are first met or waived in accordance with Section 11.01 hereof.
                                                     -------------

     "Total Tranche C Term Loan Commitment" shall mean $100,000,000, the sum of
the Tranche C Term Loan Commitments of each of the Banks identified as having
made a Tranche C Term Loan Commitment on its signature page to the Second
Amendment; provided that the Total Tranche C Term Loan Commitment may be
           --------
increased up to $200,000,000 as provided in Section 2.01(e).
                                            ---------------

     "Tranche C Term Loan Commitment" shall mean, with respect to each Bank
making such a commitment, the amount set forth opposite such Bank's name on its
signature page to the Second Amendment directly below the heading entitled
"Tranche C Term Loan Commitment."

     "Tranche C Term Loan Maturity Date" shall mean May 10, 2007.

     "Tranche C Term Note" shall have the meaning provided in Section 2.02.
                                                              ------------

     Section 2.2  Amendment to Section 2.01.  Section 2.01 of the Credit
                  -------------------------   ------------
Agreement is hereby amended to include new clauses (d) and (e) to read in their
entirety as follows:

          (d)     Tranche C Term Loans. Subject to the terms and conditions
                  --------------------
     hereof, each Bank with a Tranche C Term Loan Commitment severally agrees at
     the closing of the Second Amendment to be held on the Second Amendment
     Effective Date, to make a single advance of a term loan (each a "Tranche C
                                                                      ---------
     Term Loan") to the Company not to exceed at any time outstanding the
     ---------
     maximum amount of its Tranche C Term Loan Commitment, which Loans (i)
     shall, at the option of the Company, be made and maintained pursuant to one
     or more Advances comprised of Alternate Base Rate Advances or Eurodollar
     Rate Advances, provided that, except as otherwise specifically provided
                    --------
     herein, (ii) in the case of Eurodollar Rate Advances, shall be made in the
     minimum amount of $5,000,000 and integral multiples of $1,000,000 and, in
     the case of Alternate Base Rate Advances, in the minimum amount of
     $1,000,000 and integral multiples of $500,000, (iii) may be repaid (but not
     reborrowed) at the option of the Company in accordance with the provisions
     hereof, and (iv) shall, in the aggregate at any time outstanding, not
     exceed the Total Tranche C Term Loan Commitment. There shall be no further
     Advances of Tranche C Term Loans after the Second Amendment Effective Date
     except as provided in Section 2.01(e).
                           ---------------

          (e)     Additional Tranche C Term Loans.  The Borrower shall have the
                  -------------------------------
     right, subject to the approval of the Administrative Agent (which consent
     shall not be unreasonably withheld), to effectuate from time to time an
     increase in the Total Tranche C Term Loan Commitments under this Agreement
     by adding to this Agreement one or more financial institutions ("Additional
     Tranche C Banks") (who shall, upon completion

                                     Page 5
<PAGE>

     of the requirements stated in this Section 2.01(e), become Banks for all
                                        ---------------
     purposes hereunder), or by allowing one or more Banks to increase their
     Tranche C Term Loan Commitment hereunder, so that such added and increased
     Tranche C Term Loan Commitments shall equal the increase in Total Tranche C
     Term Loan Commitments effectuated pursuant to this Section 2.01(e);
                                                        ---------------
     provided that the Total Tranche C Term Loan Commitments cannot exceed
     $200,000,000. The Borrower shall give the Administrative Agent three
     Business Days' notice of the Borrower's intention to increase the Total
     Tranche C Term Loan Commitments pursuant to this Section 2.01(e). Such
                                                      ---------------
     notice shall specify each Additional Tranche C Bank, if any, the changes in
     amounts of Total Tranche C Term Loan Commitments that will result, the
     terms and conditions of such Tranche C Term Loans and such other
     information as is reasonably requested by the Administrative Agent. Each
     Additional Tranche C Bank, and each Bank agreeing to increase its Tranche C
     Term Loan Commitment, shall execute and deliver to the Administrative Agent
     a certificate in form reasonably satisfactory to the Administrative Agent
     ("Additional Tranche C Term Loan Commitment Certificate") pursuant to which
       -----------------------------------------------------
     it becomes a party hereto or increases its Tranche C Term Loan Commitment,
     as the case may be, which Additional Tranche C Term Loan Commitment
     Certificate, in the case of an Additional Tranche C Bank, shall attach the
     Prescribed Forms. In addition, the Borrower shall execute and deliver a
     Note in the principal amount of the Tranche C Term Loan Commitment of each
     Additional Tranche C Bank, or a replacement Note in the principal amount of
     the increased Tranche C Term Loan Commitment of each Bank agreeing to
     increase its Tranche C Term Loan Commitment, as the case may be. On the
     effective date of the Additional Tranche C Term Loan Commitment Certificate
     executed by such Additional Tranche C Bank, if any, or a preexisting Bank,
     as the case may be, such Additional Tranche C Bank (or preexisting Bank, if
     applicable) shall advance to the Administrative Agent, for payment to the
     Borrower, a single advance in the amount of its Tranche C Term Loan
     Commitment, or increase thereof, as applicable, which advance shall be
     deemed to be a Tranche C Term Loan under this Agreement. Such additional
     Tranche C Term Loans may have different interest rates and a later maturity
     than the existing Tranche C Term Loans and an amortization rate based on
     such later maturity (with correlative changes to the pertinent provisions
     of this Agreement deemed made), provided that, even though such advance may
     have a later maturity than the Tranche C Term Loans under the Second
     Amendment, in the event of prepayment, such advances shall be paid pro rata
     with and on the same terms as the Tranche C Term Loans originally advanced
     pursuant to the Second Amendment.

     Section 2.3  Amendment to Section 2.02. The Credit Agreement is hereby
                  -------------------------
amended to include a new sentence at the end of Section 2.02 to read in its
                                                ------------
entirety as follows:

     The Tranche C Term Loans shall be evidenced by a Note in favor of each Bank
     (individually a "Tranche C Term Note" and collectively, the "Tranche C Term
                      -------------------                         --------------
     Notes") substantially in the form of Exhibit 2.02(d) hereto.
     -----

     Section 2.4  Amendment to Section 2.06.  Section 2.06 of the Credit
                  -------------------------   ------------
Agreement is hereby amended to read in its entirety as follows:

                                     Page 6
<PAGE>

          Section 2.06  Voluntary Prepayments.  Upon at least one (1) Business
                        ---------------------
     Day prior written notice given before 12:00 noon (Dallas, Texas time), the
     Company shall have the right to voluntarily prepay the Loans in whole or in
     part at any time on the following terms and conditions: no Eurodollar Rate
     Advance may be prepaid prior to the last day of its Interest Period unless,
     simultaneously therewith, the Company pays to the Administrative Agent for
     the benefit of the Banks all sums necessary to compensate the Banks for all
     reasonable costs and expenses actually incurred by the Banks as a result of
     such prepayment (excluding loss of anticipated profits), as reasonably
     determined by the Banks, including but not limited to those costs described
     in Section 2.15 hereof; and each prepayment pursuant to this section shall
        ------------
     be applied first, to the payment of Swingline Advances, thereafter to
     accrued and unpaid interest, then, to Revolving Loans if so designated by
     the Company (provided no Default or Event of Default then exists) and
     otherwise pro rata to reduce the principal installments due under the Term
     Loans in the order of their maturity; provided, however, that any voluntary
                                           --------  -------
     prepayment of the Tranche C Term Loans made on or prior to May 10, 2001
     shall include a premium of 2% of the principal amount prepaid and any
     voluntary prepayment of the Tranche C Term Loans made after May 10, 2001
     and on or prior to May 10, 2002 shall include a premium of 1% of the
     principal amount prepaid.

     Section 2.5  Amendment to Section 2.07(a).  Section 2.07(a) of the Credit
                  ----------------------------   ---------------
Agreement is hereby amended to read in its entirety as follows:

          (a)     Repayment of the Term Loans.

          The Company shall pay to the Administrative Agent for the account of
     the Banks who hold Term Loans the aggregate principal amount of the Term
     Loans advanced in installments as follows:

          (i)     (A) In the case of the Tranche A Term Loans and the Tranche B
          Term Loans , Twenty-Four consecutive principal installments due and
          payable on each Designated Payment Date commencing on the first
          Designated Payment Date after the Effective Date and continuing on
          each Designated Payment Date thereafter, through and including the
          Designated Payment Date just prior to the Term Loan Maturity Date in
          an amount equal to 1/4% of the Tranche A Term Loan outstanding on the
          first Designated Payment Date or the Tranche B Term Loan outstanding
          on the first Designated Payment Date, as applicable; and (B) in the
          case of the Tranche C Term Loans, Twenty-Seven consecutive principal
          installments due and payable on each Designated Payment Date
          commencing on the first Designated Payment Date after the Second
          Amendment Effective Date and continuing on each Designated Payment
          Date thereafter, through and including the Designated Payment Date
          just prior to the Tranche C Term Loan Maturity Date in an amount equal
          to 1/4% of the Tranche C Term Loan outstanding on the first Designated
          Payment Date after the Second Amendment Effective Date; and

                                     Page 7
<PAGE>

          (ii)    In any event, (A) all unpaid Obligations in respect of the
          Tranche A Term Loans and the Tranche B Term Loans will be due and
          payable on the Term Loan Maturity Date and (B) all unpaid Obligations
          in respect of the Tranche C Term Loans will be due and payable on the
          Tranche C Term Loan Maturity Date.

     Section 2.6  Amendment to Section 5.14(a).  The Credit Agreement is hereby
                  ----------------------------
amended to include a new sentence at the end of Section 5.14(a) to read in its
                                                ---------------
entirety as follows:

     The proceeds of the Tranche C Term Loans shall be used:  (A) to provide for
     working capital; (B) to refinance the outstanding amount of certain
     existing Indebtedness of the Company; (C) to finance capital expenditures;
     and (D) for other lawful corporate purposes not prohibited by this
     Agreement.

     Section 2.7  Amendment to Section 11.10.  Clauses (c) and (d) of Section
                  --------------------------   ------------------------------
11.10 of the Credit Agreement are hereby amended to read in their entirety as
-----
follows:

     (c)  A Bank may assign to any other Bank or Banks or to any Affiliate of a
Bank and, with the prior written consent (which consent shall not be
unreasonably withheld) of the Company (so long as no Default or Event of Default
then exists) and the Administrative Agent, a Bank may assign to one or more
other Eligible Assignees all or a portion of its interests, rights, and
obligations under this Agreement and the other Loan Documents (including all or
a portion of its Commitments (or any of them) and the same or varying portions
of the Loans and other Obligations of the Company at the time owing to it and
the Notes (or any of them) held by it); provided, however, that (i) except in
                                        --------  -------
the case of an assignment to another Bank, an Affiliate of an existing Bank or
any fund that invests in bank loans and is advised or managed by an investment
advisor to an existing Bank or an assignment of all of a Bank's rights and
obligations under this Agreement, each such assignment shall be in a minimum
principal amount of not less than $5,000,000, (ii) the parties to each such
assignment shall execute and deliver to the Administrative Agent, for its
acceptance, an Assignment and Acceptance, substantially in the form of Exhibit
                                                                       -------
11.10(c) hereto, in form and substance satisfactory to the Administrative Agent
--------
(an "Assignment and Acceptance") and any Note subject to such assignment, (iii)
     -------------------------
no assignment shall be effective until receipt by the Administrative Agent of a
reasonable service fee from the Assignee Bank in respect of said assignment
equal to $3,500, (iv) the Assigning Bank, provided it does not assign all of its
rights and obligations under this Agreement and the other Loan Documents, shall
retain a minimum amount of $5,000,000 of the Commitments following the
Assignment and (v) each such assignment is subject to Section 2.17.  Upon such
                                                      ------------
execution, delivery and acceptance, from and after the effective date specified
in each Assignment and Acceptance, which effective date (unless otherwise agreed
to by the assigning Bank, the Eligible Assignee thereunder and the
Administrative Agent) shall be at least five Business Days after the execution
thereof, (x) the Eligible Assignee thereunder shall be a party hereto as a
"Bank" and to the other Loan Documents and, to the extent provided in such
Assignment and Acceptance, have the rights and obligations of a Bank hereunder
and under the other Loan Documents and (y) the assignor Bank thereunder shall,
to the extent provided in such Assignment and Acceptance, be released from its
obligations under this Agreement and the other Loan Documents (and, in the case
of an Assignment and Acceptance covering all of the remaining portion of an
assigning

                                     Page 8
<PAGE>

Bank's rights and obligations under this Agreement and the other Loan Documents,
such Bank shall cease to be a party hereto).

     (d) Any Bank may at any time assign all or any portion of its rights under
this Agreement and its Note (i) to a Federal Reserve Bank or (ii) in the case of
any Bank which is an investment fund, to the trustee under the indenture to
which such fund is a party in support of its obligations to such trustee for the
benefit of the applicable trust beneficiaries.  No such assignment shall release
the transferor Bank from its obligations hereunder.

     Section 2.8  Addition of Exhibit 2.02(d).  The Credit Agreement is hereby
                  ---------------------------
amended to include a new Exhibit 2.02(d) to read in its entirety as set forth in
                         ---------------
Annex A hereto.

                                   ARTICLE 3

                 Ratifications, Representations and Warranties
                 ---------------------------------------------

     Section 3.1  Ratifications.  The terms and provisions set forth in this
                  -------------
Amendment shall modify and supersede all inconsistent terms and provisions set
forth in the Credit Agreement and except as expressly modified and superseded by
this Amendment, the terms and provisions of the Credit Agreement and the other
Loan Documents are ratified and confirmed and shall continue in full force and
effect.  The Company and the Banks agree that the Credit Agreement as amended
hereby and the other Loan Documents shall continue to be legal, valid, binding
and enforceable in accordance with their respective terms, except, in each case,
as such enforceability may be limited by bankruptcy, insolvency, reorganization,
moratorium, fraudulent transfer or other similar laws relating to or affecting
the enforcement of creditors' rights generally, and by general principles of
equity regardless of whether such enforceability is sought in a proceeding in
equity or at law.

     Section 3.2  Representations and Warranties.  The Company hereby represents
                  ------------------------------
and warrants to the Banks that (i) the execution, delivery and performance of
this Amendment and any and all other Loan Documents executed and/or delivered in
connection herewith have been authorized by all requisite action on the part of
the Company and will not violate the certificate or articles of incorporation,
other organizational documents or bylaws of the Company or any Guarantor; (ii)
the representations and warranties contained in the Credit Agreement and any
other Loan Document are true and correct in all material respects on and as of
the date hereof as though made on and as of the date hereof (except to the
extent that such representations and warranties were expressly, in the Credit
Agreement, made only in reference to a specific date); and (iii) no Default or
Event of Default has occurred and is continuing.

                                   ARTICLE 4

                                 Miscellaneous
                                 -------------

     Section 4.1  Conditions to Effectiveness.  This Amendment shall be
                  ---------------------------
effective upon the execution hereof by the Company, Majority Banks party to the
Credit Agreement prior to the Second Amendment Effective Date, all Banks having
made Tranche C Term Loan Commitments

                                     Page 9
<PAGE>

and the Administrative Agent and upon delivery to the Administrative Agent of
each of the following documents and fulfillment of the following conditions, all
in form and substance reasonably satisfactory to the Administrative Agent:

     (a) Resolutions.  Resolutions of the board of directors or other
         -----------
     appropriate body of the Company and each Subsidiary certified by its
     Secretary or an Assistant Secretary or other analogous officer or
     representative which authorize the execution, delivery and performance by
     such Person of this Amendment and such other Loan Documents to be executed
     in connection herewith to which it is or is to be a party or a certificate
     of such officer attached to a copy of such documents previously delivered
     certifying that the information in such documents is true and correct as of
     such effective date as though dated the date thereof;

     (b) Incumbency Certificate.  A certificate of incumbency certified by the
         ----------------------
     Secretary or an Assistant Secretary or other analogous officer or
     representative of the Company and each Subsidiary certifying as to the name
     of each officer or other representative of such Person (i) who is
     authorized to sign this Amendment or any Loan Documents to which such
     Person is or is to be a party (including any certificates contemplated
     herein), together with specimen signatures of each such officer or other
     representative, and (ii) who will, until replaced by other officers or
     representatives duly authorized for that purpose, act as its representative
     for the purposes of signing documents and giving notices and other
     communications in connection with the Loan Documents and the transactions
     contemplated thereby or a certificate of such officer attached to a copy of
     such documents previously delivered certifying that the information in such
     documents is true and correct as of such effective date as though dated the
     date thereof;

     (c) Articles or Certificates of Incorporation, etc.  Certified copies of
         ----------------------------------------------
     any amendments of or other changes to the articles or certificates of
     incorporation, certificate of formation, certificate of limited
     partnership, partnership agreement or other analogous constitutional
     document of the Company and each Subsidiary since March 23, 2000, certified
     by the Secretary of State or other applicable Governmental Authority of the
     state or other jurisdiction of incorporation or organization of such Person
     and dated as of a current date;

     (d) Bylaws.  Certified copies of any amendments of or other changes to the
         ------
     bylaws or other analogous constitutional document of the Company and each
     Subsidiary since March 23, 2000, certified by the Secretary or an Assistant
     Secretary or other analogous officer or representative of such Person;

     (e) Government Certificates.  Certificates of appropriate officials as to
         -----------------------
     the existence and good standing, status or compliance, as applicable, of
     the Company and each Subsidiary, reasonably requested by the Administrative
     Agent, in their respective jurisdictions of incorporation or organization
     and any and all jurisdictions where such Person is qualified to do business
     as a foreign corporation or other entity, each such certificate to be dated
     as of a current date or a certificate of such officer attached to a copy of
     such documents previously delivered certifying that the information in such
     documents is true and correct as of such effective date as though dated the
     date thereof;

                                    Page 10
<PAGE>

     (f) Payment of Fees and Expenses. The payment to the Administrative Agent
         ----------------------------
     and the Banks of all reasonable fees and expenses agreed upon by such
     parties to be paid on the Effective Date;

     (g) No Prohibitions.  No Governmental Requirement shall prohibit the
         ---------------
     consummation of the transactions contemplated by this Amendment or any
     other Loan Document to be delivered in connection herewith, and no order,
     judgment or decree of any Governmental Authority or arbitrator shall, and
     no litigation or other proceeding shall be pending or threatened which
     would, enjoin, prohibit, restrain or otherwise adversely affect the
     consummation of the transactions contemplated by this Amendment or the
     other Loan Documents to be delivered in connection herewith;

     (h) Opinion of Counsel.  Opinion addressed to the Administrative Agent and
         ------------------
     the Banks from Bracewell & Patterson, L.L.P. and the General Counsel to the
     Company, as to such matters as the Administrative Agent may reasonably
     request;

     (i) Proceedings Satisfactory.  All matters and proceedings taken in
         ------------------------
     connection with this Amendment and the other Loan Documents to be delivered
     in connection herewith shall be reasonably satisfactory to the
     Administrative Agent and its counsel.

Borrower shall deliver, or cause to be delivered, to the Administrative Agent
sufficient counterparts of each agreement, document or instrument to be received
by the Administrative Agent under this Section 4.1 to permit the Administrative
                                       -----------
Agent to distribute a copy of the same to each Bank.

     Section 4.2  Survival of Representations and Warranties.  All
                  ------------------------------------------
representations and warranties made in this Amendment or any other Loan Document
including any Loan Document furnished in connection with this Amendment shall
survive the execution and delivery of this Amendment and the other Loan
Documents, and no investigation by the Banks or the Administrative Agent shall
affect the representations and warranties or the right of the Banks or the
Administrative Agent to rely upon them.

     Section 4.3  Reference to Credit Agreement.  Each of the Loan Documents,
                  -----------------------------
including the Credit Agreement and any and all other agreements, documents, or
instruments now or hereafter executed and delivered pursuant to the terms hereof
or pursuant to the terms of the Credit Agreement as amended hereby, are hereby
amended so that any reference in such Loan Documents to the Credit Agreement
shall mean a reference to the Credit Agreement as amended hereby.

     Section 4.4  Expenses of Agent.  As provided in the Credit Agreement, the
                  -----------------
Company agrees to pay on demand all costs and expenses incurred by the
Administrative Agent in connection with the preparation, negotiation, and
execution of this Amendment and the other Loan Documents executed pursuant
hereto.

                                    Page 11
<PAGE>

     Section 4.5  Severability.  Any provision of this Amendment held by a court
                  ------------
of competent jurisdiction to be invalid or unenforceable shall not impair or
invalidate the remainder of this Amendment and the effect thereof shall be
confined to the provision so held to be invalid or unenforceable.

     Section 4.6  Applicable Law.  THIS AMENDMENT SHALL BE GOVERNED BY AND
                  --------------
CONSTRUED IN ACCORDANCE WITH THE LAWS OF THE STATE OF TEXAS AND THE APPLICABLE
LAWS OF THE UNITED STATES OF AMERICA.

     Section 4.7  Successors and Assigns.  This Amendment is binding upon and
                  ----------------------
shall inure to the benefit of the Company, the Banks and the Administrative
Agent and their respective successors and assigns, except that the Company may
not assign or transfer any of its rights or obligations hereunder without the
prior written consent of the Banks.

     Section 4.8  Counterparts.  This Amendment may be executed in one or more
                  ------------
counterparts, and on telecopy counterparts each of which when so executed shall
be deemed to be an original, but all of which when taken together shall
constitute one and the same agreement.

     Section 4.9  Effect of Waiver.  No consent or waiver, express or implied,
                  ----------------
by the Banks to or for any breach of or deviation from any covenant, condition
or duty by the Company or any Guarantor shall be deemed a consent or waiver to
or of any other breach of the same or any other covenant, condition or duty.

     Section 4.10  Headings.  The headings, captions, and arrangements used in
                   --------
this Amendment are for convenience only and shall not affect the interpretation
of this Amendment.

     Section 4.11  ENTIRE AGREEMENT.  THIS AMENDMENT AND ALL OTHER INSTRUMENTS,
                   ----------------
DOCUMENTS AND AGREEMENTS EXECUTED AND DELIVERED IN CONNECTION WITH THIS
AMENDMENT EMBODY THE FINAL, ENTIRE AGREEMENT AMONG THE PARTIES HERETO AND
SUPERSEDE ANY AND ALL PRIOR COMMITMENTS, AGREEMENTS, REPRESENTATIONS AND
UNDERSTANDINGS, WHETHER WRITTEN OR ORAL, RELATING TO THIS AMENDMENT, AND MAY NOT
BE CONTRADICTED OR VARIED BY EVIDENCE OF PRIOR, CONTEMPORANEOUS OR SUBSEQUENT
ORAL AGREEMENTS OR DISCUSSIONS OF THE PARTIES HERETO.  THERE ARE NO ORAL
AGREEMENTS AMONG THE PARTIES HERETO.

     Section 4.12  Reaffirmation of Guaranty and Security Documents.  The
                   ------------------------------------------------
undersigned Company and each of the Guarantors of the obligations of the Company
to the Banks under the Credit Agreement and the other Loan Documents each
hereby: (i) consents to the execution and delivery of the foregoing Amendment,
(ii) agrees that the Amendment shall not limit or diminish the obligations of
the undersigned under the Credit Agreement as the Company or as Guarantors or
under any of the Security Documents as pledgors, debtors, grantors or otherwise,
(iii) reaffirms its obligations under its Guaranty, in the case of the
Guarantors, and each Security Document, (iv) agrees that the Guaranty and each
Security Document remains in full force and effect and is hereby ratified and
confirmed and (v) agrees that each reference in the Guaranty and

                                    Page 12
<PAGE>

each Security Document to the "Obligations," the "Guaranteed Obligations," the
"Secured Obligations," or any analogous term shall include, without limitation,
all obligations to pay or otherwise in respect of the Tranche C Term Loans.

             [The remainder of this page intentionally left blank]

                                    Page 13
<PAGE>

     IN WITNESS WHEREOF, the parties hereto have caused this Agreement to be
executed by their respective officers thereunto duly authorized as of the date
first above written.

                              THE COMPANY:

                              ENCOMPASS SERVICES CORPORATION

                              By:    /s/ DARREN B. MILLER
                                     ---------------------------
                              Name:  Darren B. Miller
                              Title: Senior Vice President

                                    Page 14
<PAGE>

GUARANTORS:
----------

ADVENT ELECTRIC CO., INC.
AMERICAN AIR COMPANY, INC.
ATLANTIC ELECTRIC COMPANY, INC.
BARNES IVEY MECHANICAL COMPANY, L.L.C., By Ivey Mechanical Company, Inc.
B&R ELECTRICAL SERVICES, INC.
BELTLINE MECHANICAL SERVICES, INC.
BRAZOSPORT MANAGEMENT, INC.
BUILDING ONE COMMERCIAL, INC. (F/K/A SPANN BUILDING MAINTENANCE COMPANY, TO BE
NAMED ENCOMPASS COMMERCIAL, INC.)
BUILDING ONE SERVICE SOLUTIONS, INC.
BUYR, INC.
CHAMBERS ELECTRONIC COMMUNICATIONS, INC.
CONSOLIDATED ELECTRICAL GROUP, INC.
CRAMAR ELECTRIC, INC.
C.R. HIPP CONSTRUCTION CO., INC.
D&P JANITORIAL, INC.
DEL-AIR SERVICE COMPANY, INC.
D/FW MECHANICAL SERVICES, INC.
DIRECT ENGINEERED MAINTENANCE, INC.
DIVERSIFIED MANAGEMENT SERVICES, U.S.A., INC.
EDG POWER GROUP, INC.
ELECTRICAL CONTRACTING, INC.
ELECTRICAL DESIGN & CONSTRUCTION, INC.
ENCOMPASS MECHANICAL SERVICES, INC. (FORMERLY BUILDING ONE MECHANICAL SERVICES,
INC.)
ENGINEERING DESIGN GROUP, INC.
FACILITYDIRECT.COM, LLC (F/K/A ALLIANCE SUPPLY CO., LLC), By Building One
Services Solutions, Inc.
FRED CLARK ELECTRICAL CONTRACTOR, INC.
GAMEWELL MECHANICAL, INC.
GARFIELD-INDECON ELECTRICAL SERVICES, INC.
G.S. FINANCIAL, INC.
G.S. GROUP, INC.
G.S.I. OF CALIFORNIA, INC.
GULF STATES, INC.
HYDRO COOLING, INC.
INTERSTATE BUILDING SERVICES, LLC, By Building One Service Solutions, Inc.
IVEY MECHANICAL COMPANY, INC.
IVEY MECHANICAL SERVICES, L.L.C., By Ivey Mechanical Company, Inc.
K & A MECHANICAL, INC.
THE LEWIS COMPANIES, INC.
LEXINGTON/IVEY MECHANICAL COMPANY, LLC, By Ivey Mechanical Company, Inc.

<PAGE>

MCINTOSH MECHANICAL, INC.
MH TECHNOLOGIES, INC.
NATIONAL NETWORK SERVICES, INC.
OIL CAPITAL ELECTRIC, INC.
OMNI MECHANICAL COMPANY
OMNI MECHANICAL SERVICES, By Omni Mechanical Company
POTTER ELECTRIC CO., INC.
PROCESS DESIGN BUILDERS, LLC, By Sanders Bros., Inc.
PRO WIRE SECURITY SYSTEMS, INC.
REGENCY ELECTRIC COMPANY, INC.
REGENCY ELECTRIC COMPANY ATLANTA OFFICE
REGENCY ELECTRIC COMPANY CHARLOTTE OFFICE, INC.
REGENCY ELECTRIC COMPANY JACKSONVILLE OFFICE, INC.
REGENCY ELECTRIC COMPANY MEMPHIS OFFICE, INC.
REGENCY ELECTRIC COMPANY ORLANDO OFFICE, INC.
REGENCY ELECTRIC COMPANY PROJECTS GROUP, INC.
REGENCY ELECTRIC COMPANY SOUTH FLORIDA OFFICE, INC.
RIVIERA ELECTRIC CONSTRUCTION CO.
RIVIERA ELECTRIC OF CALIFORNIA, INC.
ROBINSON MECHANICAL COMPANY
SANDERS BROS, INC.
SKC ELECTRIC, INC.
SKCE, INC.
S.L. PAGE CORPORATION
SULLIVAN ELECTRIC, INC.
TAYLOR-HUNT ELECTRIC, INC. (F/K/A TAYLOR ELECTRIC, INC.)
TESTRONICS, INC.
TOWN & COUNTRY ELECTRIC, INC.
TRI-CITY ELECTRICAL CONTRACTORS, INC.
TRI-M BUILDING AUTOMATION SYSTEMS CORP.
TRI-M CORPORATION
TRI-M ELECTRICAL CONSTRUCTION CORP.
TRI-M HOLDING CORP.
TSE ACQUISITION CORP.
TRI-STATE ACQUISITION CORP.
WALKER ENGINEERING, INC.
WALTER C. DAVIS & SON, INCORPORATED
WATSON ELECTRICAL CONSTRUCTION CO.
WILSON ELECTRIC COMPANY, INC.
WAYZATA, INC.
ZWART, INC. (D/B/A MOUNTAIN VIEW ELECTRIC, INC.)

AA ADVANCE AIR, INC.
AA JARL, INC.
A-ABC APPLIANCE, INC.
A-ABC SERVICES, INC.
A-1 MECHANICAL OF LANSING, INC.

<PAGE>

AIR CONDITIONING ENGINEERS, INC.
AIR CONDITIONING, PLUMBING & HEATING SERVICE CO., INC.
AIRCON ENERGY INCORPORATED
AIR SYSTEMS, INC.
AIRTRON, INC.
AIRTRON OF CENTRAL FLORIDA, INC.
ALL SERVICE ELECTRIC, INC.
ARKANSAS MECHANICAL SERVICES, INC.
ATLANTIC INDUSTRIAL CONSTRUCTORS, INC.
CALLAHAN ROACH PRODUCTS & PUBLICATIONS, INC.
CARDINAL CONTRACTING CORPORATION
CENTRAL AIR CONDITIONING CONTRACTORS, INC.
CENTRAL CAROLINA AIR CONDITIONING COMPANY
CHAPEL ELECTRIC CO.
CHARLIE CRAWFORD, INC.
CLARK CONVERSE ELECTRIC SERVICE, INC.
COLONIAL AIR CONDITIONING COMPANY
COMMERCIAL AIR HOLDING COMPANY
COMMERCIAL AIR, POWER & CABLE, INC.
CONTINENTAL ELECTRICAL CONSTRUCTION CO.
COSTA AND RIHL, INC.
COSTA & RIHL PLUMBING, INC.
COSTNER BROTHERS, INC.
DIVCO, INC.
DYNALINK CORPORATION
ELECTRICAL ASSOCIATES OF DALLAS, INC.
ENCOMPASS FACILITY SERVICES, INC. (FORMERLY GROUPMAC FACILITY SERVICES, INC.)
ENCOMPASS SERVICES HOLDING CORP. (FORMERLY GROUPMAC HOLDING CORP.)
ENCOMPASS SERVICES INDIANA, L.L.C. (FORMERLY GROUPMAC INDIANA, L.L.C,  By
Airtron, Inc., Paul E. Smith Co., Inc., and Cardinal Contracting Corporation
EVANS SERVICES, INC.
THE FARFIELD COMPANY
FERGUSON ELECTRIC CORPORATION
GENTZLER ELECTRICAL CONTRACTORS, INC.
GILBERT MECHANICAL CONTRACTORS, INC.
GROUPMAC MARYLAND CORP. (TO BE NAMED ENCOMPASS MARYLAND CORP.)
GROUPMAC TEXAS L.P. (TO BE NAMED ENCOMPASS TEXAS L.P.), By Encompass Services
Holding Corp.
HPS PLUMBING SERVICES, INC.
HALLMARK AIR CONDITIONING, INC.
HUNGERFORD MECHANICAL CORPORATION
J. D. STEWARD AIR CONDITIONING, INC.
K & N PLUMBING, HEATING AND AIR CONDITIONING, INC.
LANEY'S, INC.
LINFORD SERVICE CO.
L.T. MECHANICAL, INC.
MACDONALD-MILLER CO., INC.

<PAGE>

MACDONALD-MILLER INDUSTRIES, INC.
MACDONALD-MILLER OF OREGON, INC.
MACDONALD-MILLER SERVICE, INC.
MASTERS, INC.
MECHANICAL INTERIORS, INC.
MECHANICAL SERVICES OF ORLANDO, INC.
MERRITT ISLAND AIR & HEAT, INC.
NEW CONSTRUCTION AIR CONDITIONING, INC.
NORON, INC.
PACIFIC RIM MECHANICAL CONTRACTORS, INC.
PAUL E. SMITH CO., INC.
PHOENIX ELECTRIC COMPANY
RAY AND CLAUDE GOODWIN, INC.
RELIABLE MECHANICAL, INC.
ROMANOFF ELECTRIC CORP.
SEQUOYAH CORPORATION
SIBLEY SERVICES, INCORPORATED
SNYDER MECHANICAL
SOUTHEAST MECHANICAL SERVICE, INC.
STATEWIDE HEATING & AIR CONDITIONING, INC.
STEPHEN C. POMEROY, INC.
STERLING AIR CONDITIONING, INC.
SUN PLUMBING, INC.
TEAM MECHANICAL, INC.
TOWER ELECTRIC COMPANY
TRINITY CONTRACTORS, INC.
UNITED ACQUISITION CORP.
VALLEY WIDE PLUMBING AND HEATING, INC.
VAN'S COMFORTEMP AIR CONDITIONING, INC.
VANTAGE MECHANICAL CONTRACTORS, INC.
VERMONT MECHANICAL, INC.
WADE'S HEATING & COOLING, INC.
WIEGOLD & SONS, INC.
WILLIS REFRIGERATION, AIR CONDITIONING & HEATING, INC.
YALE INCORPORATED

By:    /s/ DARREN B. MILLER
       --------------------
Name:  Darren B. Miller
Title: Vice President
       Acting on Behalf of Each of the Above

<PAGE>

ENCOMPASS MANAGEMENT CO. (formerly GroupMac Management Co.)

By:    /s/ DARREN B. MILLER
       --------------------
Name:  Darren B. Miller
Title: Executive Vice President

<PAGE>

                                    ADMINISTRATIVE AGENT/BANK:

Tranche C                           BANK OF AMERICA, N.A.
Term Loan Commitment                as Administrative Agent and Individually, as
                                    a Bank
$25,000,000

                                    By: /s/ RICHARD L. NICHOLS, JR.
                                       ----------------------------
                                    Name:  Richard L. Nichols, Jr.
                                    Title: Managing Director

<PAGE>

                                    SYNDICATION-AGENT/BANK:

Tranche C                           CHASE BANK OF TEXAS,
Term Loan Commitment                NATIONAL ASSOCIATION
                                    as Syndication Agent and
$10,000,000                         Individually, as a Bank

                                    By:    /s/ JAMES R. DOLPHIN
                                           ------------------------------
                                    Name:  James R. Dolphin
                                    Title: Senior Vice President

<PAGE>

                                    DOCUMENTATION AGENT/BANK:

Tranche C                           FIRST UNION NATIONAL BANK
Term Loan Commitment                as Documentation Agent and
None                                Individually, as a Bank

                                    By:    /s/ DAVID C. HAUGLID
                                           -----------------------------
                                    Name:  David C. Hauglid
                                    Title: Vice President

<PAGE>

                              BANKS:

Tranche C                     ABN-AMRO BANK NV
Term Loan Commitment
None
                              By:    /s/ LAURIE C. TUZO
                                     ------------------------------
                              Name:  Laurie C. Tuzo
                              Title: Senior Vice President

                              By:    /s/ ERIC R. HOLLINGSWORTH
                                     ------------------------------
                              Name:  Eric R. Hollingsworth
                              Title: Vice President

<PAGE>

Tranche C                           BANK AUSTRIA CREDITANSTALT
Term Loan Commitment                CORPORATE FINANCE, INC.
None

                                    By:    ______________________________
                                    Name:  Stephen W. Hipp
                                    Title: Senior Associate

                                    By:    ______________________________
                                    Name:  John G. Taylor
                                    Title: Vice President

<PAGE>

Tranche C                           BANK LEUMI USA
Term Loan Commitment
None
                                    By:    /s/ JOUNG HEE HONG
                                           -------------------------
                                    Name:  Joung Hee Hong
                                    Title: Vice President

<PAGE>

Tranche C                           THE GOVERNOR AND COMPANY OF
Term Loan Commitment                THE BANK OF IRELAND
None

                                    By:    /s/ BRENDAN MCLOUGLIN
                                           ---------------------
                                    Name:  Brendan McLouglin
                                    Title: Manager

                                    By:    /s/ MARY CONNOLLY
                                           ------------------------------
                                    Name:  Mary Connolly
                                    Title: Senior Account Executive

<PAGE>

Tranche C                           THE BANK OF NOVA SCOTIA
Term Loan Commitment
None

                                    By:    /s/ F.C.H. Ashby
                                           -------------------------------
                                    Name:  F.C.H. Ashby
                                    Title: Senior Manager Loan Operations

<PAGE>

Tranche C                           BANK ONE, N.A.
Term Loan Commitment
None

                                    By:    John J. Zellinger, IV
                                           -------------------------------
                                    Name:  John J. Zellinger, IV
                                    Title: Vice President

                                    By:    _______________________________
                                    Name:  _______________________________
                                    Title: _______________________________

<PAGE>

Tranche C                           BANKBOSTON, N.A.
Term Loan Commitment
None

                                    By:    _______________________________
                                    Name:  _______________________________
                                    Title: _______________________________

<PAGE>

Tranche C                           BANKERS TRUST COMPANY
Term Loan Commitment
None

                                    By:    /s/ PADDY DOWLING
                                           --------------------------
                                    Name:  Paddy Dowling
                                    Title: Vice President

<PAGE>

Tranche C                           CITICORP USA, INC.
Term Loan Commitment
None

                                    By:    /s/ MARK R. FLOYD
                                           ------------------------------
                                    Name:  Mark R. Floyd
                                    Title: Vice President

<PAGE>

Tranche C                           COMERICA BANK
Term Loan Commitment
None

                                    By:    /s/ MARK B. GROVER
                                           ------------------------------
                                    Name:  Mark B. Grover
                                    Title: First Vice President

<PAGE>

Tranche C                           MANAGING AGENT/LENDER:
Term Loan Commitment
None                                CREDIT LYONNAIS,
                                    New York Branch

                                    By:    /s/ ROBERT IVOSEVICH
                                           -------------------------------
                                    Name:  Robert Ivosevich
                                    Title: Senior Vice President

<PAGE>

Tranche C                           GMAC COMMERCIAL CREDIT LLC
Term Loan Commitment
None
                                    By:    _______________________________
                                    Name:  _______________________________
                                    Title: _______________________________

                                    By:    _______________________________
                                    Name:  _______________________________
                                    Title: _______________________________

<PAGE>

Tranche C                           HELLER FINANCIAL, INC.
Term Loan Commitment
$15,000,000
                                    By:    /s/ DAVID R. CAMPBELL
                                           ----------------------------
                                    Name:  David R. Campbell
                                    Title: Vice President

<PAGE>

Tranche C                           MERCANTILE BANK
Term Loan Commitment                NATIONAL ASSOCIATION
None

                                    By:    /s/ GREGORY L. DRYDEN
                                           ---------------------
                                    Name:  Gregory L. Dryden
                                    Title: Vice President

<PAGE>

Tranche C                           THE MITSUBISHI TRUST AND
Term Loan Commitment                BANKING CORPORATION
None

                                    By:    __________________________
                                    Name:  __________________________
                                    Title: __________________________

<PAGE>

Tranche C                           MORGAN STANLEY DEAN WITTER
Term Loan Commitment                PRIME INCOME TRUST
$10,000,000
                                    By:    /s/ PETER GEWIRTZ
                                           -----------------
                                    Name:  Peter Gewirtz
                                    Title: Vice President

<PAGE>

Tranche C                           NATIONAL CITY BANK
Term Loan Commitment                OF KENTUCKY
None

                                    By:    __________________________
                                    Name:  __________________________
                                    Title: __________________________

<PAGE>

Tranche C                           PARIBAS
Term Loan Commitment
None
                                    By:    __________________________
                                    Name:  __________________________
                                    Title: __________________________

<PAGE>

Tranche C                           SOVEREIGN BANK
Term Loan Commitment
None
                                    By:    __________________________
                                    Name:  __________________________
                                    Title: __________________________

<PAGE>

Tranche C                           STEIN ROE FLOATING RATE
Term Loan Commitment                LIMITED LIABILITY COMPANY
$4,500,000
                                    By:    /s/ BRIAN W. GOOD
                                           ------------------------------
                                    Name:  Brian W. Good
                                    Title: Vice President,
                                           Stein Roe & Farnham
                                           Incorporated, as Advisor to
                                           the Stein Roe Floating Rate
                                           Limited Liability Company

<PAGE>

Tranche C                           LIBERTY - STEIN ROE ADVISOR
Term Loan Commitment                FLOATING RATE ADVANTAGE
$500,000                            FUND,

                                    BY:  STEIN ROE & FARNHAM
                                    INCORPORATED,
                                    as Advisor

                                    By:    /s/ BRIAN W. GOOD
                                           -----------------
                                    Name:  Brian W. Good
                                    Title: Vice President & Portfolio
                                           Manager

<PAGE>

Tranche C                           THE SUMITOMO TRUST &
Term Loan Commitment                BANKING CO., LTD.,
None                                NEW YORK BRANCH

                                    By: /s/ STEPHEN STRATICO
                                        ----------------------
                                    Name:  Stephen Stratico
                                    Title: Vice President

<PAGE>

Tranche C                               UNION BANK OF CALIFORNIA, N.A.
Term Loan Commitment
None
                                        By:    __________________________
                                        Name:  __________________________
                                        Title: __________________________

<PAGE>

Tranche C                               VAN KAMPEN INVESTMENT
Term Loan Commitment                    ADVISORY CORP.
$35,000,000
                                        By:    __________________________
                                        Name:  __________________________
                                        Title: __________________________

<PAGE>

                                    ANNEX A
                                      TO
                     SECOND AMENDMENT TO CREDIT AGREEMENT

Attached.

<PAGE>

                                                                 EXHIBIT 2.02(d)

                                    FORM OF
                              TRANCHE C TERM NOTE

                                                    Dated: _______________, 2000

     FOR VALUE RECEIVED, the undersigned, ENCOMPASS SERVICES CORPORATION, a
Texas corporation (the "Company"), HEREBY PROMISES TO PAY to the order of
_________________________________ (the "Bank") the aggregate unpaid principal
amount of the Tranche C Term Loans made by the Bank to the Company pursuant to
the Credit Agreement (as defined below) on the dates and in the amounts
specified in such Credit Agreement.

     The Company promises to pay interest on the unpaid principal amount of each
Tranche C Term Loan from the date of such Tranche C Term Loan until such
principal amount is paid in full, at such interest rates, and payable at such
dates and times, as are specified in the Credit Agreement dated as of February
22, 2000 (as the same may from time to time be amended, modified or
supplemented, the "Credit Agreement," the terms defined therein and not
otherwise defined herein being used herein as therein defined), among the
Company, the Subsidiaries of the Company party thereto, the Bank and certain
other banks that are parties thereto, Bank of America, N.A., as Administrative
Agent for the Bank and such other banks, Chase Bank of Texas, National
Association, as syndication agent, and First Union National Bank, as
documentation agent.

     Both principal and interest are payable in same day funds in lawful money
of the United States of America to Bank of America, N.A., as Administrative
Agent, at 901 Main Street, 66/th/ Floor, Dallas, Texas 75202 or at such other
place as the Administrative Agent shall designate in writing to the Company.

     This Tranche C Term Note may be held by the Bank for the account of its
Domestic Lending Office or its Eurodollar Lending Office and may be transferred
from one to the other from time to time as the Bank may determine.

     This Tranche C Term Note is one of the Tranche C Term Notes referred to in,
and is entitled to the benefits of, the Credit Agreement. The obligations of the
Company hereunder are guaranteed by the Guarantors pursuant to Article VIII of
the Credit Agreement. The Credit Agreement, among other things, (i) provides for
the making of the Tranche C Term Loans by the Bank to the Company from time to
time, the indebtedness of the Company resulting from each such Tranche C Term
Loan being evidenced by this Tranche C Term Note and (ii) contains provisions
for acceleration of the maturity hereof upon the happening of certain stated
events, also for prepayments on account of principal hereof prior to the
maturity hereof upon the terms and conditions therein specified, and to the
effect that no provision of the Credit Agreement or this Tranche C Term Note
shall require the payment or permit the collection of interest in excess of the
Highest Lawful Rate.

<PAGE>

     Except as provided in the Credit Agreement, the Company and any and all
endorses, guarantors and sureties severally waive grace, demand, presentment for
payment, notice of dishonor or default or intent to accelerate, protest and
notice of protest and diligence in collecting and bringing of suit against any
party hereto, and agree to all renewals, extensions or partial payments hereon
and to any release or substitution of security herefor, in whole or in part,
with or without notice, before or after maturity.

     This Tranche C Term Note shall be governed by, and construed and
interpreted in accordance with, the laws of the State of Texas and any
applicable laws of the United States of America.

                                        ENCOMPASS SERVICES CORPORATION

                                        By:   ________________________________
                                        Name:  Darren B. Miller
                                        Title: Executive Vice President

Source: [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00013-of-00352.parquet"}, [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00013-of-00352.parquet"}]]