EXHIBIT 31(b)
                                                                   -------------

                                  CERTIFICATION
   pursuant to Rules 13a-15 and 15d-15 of the Securities Exchange Act of 1934

I, Robert I. Lieberman, Chief Financial Officer of Thermodynetics, Inc., certify
that:

1. I have reviewed this quarterly report on Form 10-QSB of Thermodynetics, Inc.;

2. Based on my knowledge, this report does not contain any untrue statement of a
material fact or omit to state a material fact  necessary to make the statements
made, in light of the  circumstances  under which such statements were made, not
misleading with respect to the period covered by this report;

3.  Based  on my  knowledge,  the  financial  statements,  and  other  financial
information included in this report, fairly present in all material respects the
financial condition,  results of operations and cash flows of the Company as of,
and for, the periods presented in this report;

4.  The  Company's  other   certifying   officers  and  I  are  responsible  for
establishing and maintaining  disclosure  controls and procedures (as defined in
Exchange Act Rules 13a-15(e) and 15d-15(e)) and internal  control over financial
reporting  (as defined in Exchange Act Rules  13a-15(f) and  15d-15(f))  for the
Company and have:

         a) designed  such  disclosure  controls and  procedures to provide that
         material   information   relating  to  the   Company,   including   its
         consolidated  subsidiaries,  is made known to us by others within those
         entities,  particularly during the period in which this report is being
         prepared;

         b) designed such internal control over financial  reporting,  or caused
         such internal control over financial reporting to be designed under our
         supervision,  to provide reasonable assurance regarding the reliability
         of financial reporting and the preparation of financial  statements for
         external  purposes in accordance  with  generally  accepted  accounting
         principles;

         c) evaluated  the overall  effectiveness  of the  Company's  disclosure
         controls and procedures to provide that material  information  relating
         to the  registrant,  as of the end of the period covered by this report
         based on such evaluation; and

         d)  disclosed  in this  report  any  change in the  Company's  internal
         control over  financial  reporting  that occurred  during the Company's
         most recent fiscal quarter (the Company's  fourth fiscal quarter in the
         case  of  an  annual  report)  that  has  materially  affected,  or  is
         reasonably likely to materially  affect, the Company's internal control
         over financial reporting; and

5. The Company's other  certifying  officers and I have disclosed,  based on our
knowledge  and our most recent  evaluation  of internal  control over  financial
reporting,  to the Company's  auditors and the audit  committee of the Company's
Board of Directors:

         a) all significant  deficiencies and material  weaknesses in the design
         or operation of internal  control over  financial  reporting  which are
         reasonably  likely to adversely affect the Company's ability to record,
         process, summarize and report financial information; and

         b) any fraud,  whether or not  material,  that  involves  management or
         other employees who have a significant  role in the Company's  internal
         controls over financial reporting.


         Date: November 11, 2005     By:      /s/  Robert I. Lieberman
                                           -------------------------------------
                                           Robert I. Lieberman
                                           Treasurer and Chief Financial Officer