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 small business
issuer as of, and for, the periods presented in this report;

4. The small business  issuer'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 small business issuer and have:

         a) designed  such  disclosure  controls and  procedures to provide that
         material information  relating to the small business issuer,  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 small business  issuer'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 small  business  issuer's
         internal  control over  financial  reporting  that occurred  during the
         small business  issuer's most recent fiscal quarter (the small business
         issuer's  fourth fiscal  quarter in the case of an annual  report) that
         has materially affected,  or is reasonably likely to materially affect,
         the small business issuer's internal control over financial  reporting;
         and

5. The small business  issuer'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 small  business  issuer's  auditors  and the audit
committee of the small business issuer'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 small  business  issuer'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  small  business
         issuer's internal controls over financial reporting.




         Date: August 10, 2005        By:   /s/  Robert I. Lieberman
                                           -------------------------------------
                                           Robert I. Lieberman
                                           Treasurer and Chief Financial Officer


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