SecProbe.io

Mail Stop 3030
January 4, 2016

Stephen E. Pirnat
Chief Executive Officer
ClearSign Combustion Corporation
12870 Interurban Avenue South
Seattle, Washington 98168

Re: ClearSign  Combustion Corporation
  Registration Statement on Form S-3
Filed  December 29, 2015
  File No.  333-208784

Dear Mr. Pirnat :

This is to advise you that we have not reviewed and will not review your registration
statement .

We urge all persons who are responsible for the accuracy and adequacy of the disclosure
in the filing to be certain that the filing includes the information the Securities Act of 193 3 and
all applicable Securities  Act rules require.   Since the company and its management are  in
possession of all facts relating to a company’s disclosure, they are responsible for the accuracy
and adequacy of the disclosures they have made.

In the event you request acceleration of t he effective date of the pending regist ration
statement, please provide  a written statement from the company acknowledging that:

 should the Commission or the staff, acting pursuant to delegated authority, declare the
filing effective, it does not foreclos e the Commission from taking any action with respect
to the filing;

 the action of the Commission or the staff, acting pursuant to delegated authority, in
declaring the filing effective, does not relieve the company from its full responsibility for
the ad equacy and accuracy of the disclosure in the filing; and

 the company may not assert staff comments and the declaration of effectiveness as a
defense in any proceeding initiated by the Commission or any person under the federal
securities laws of the Unit ed States.

Please refer to Rules 460 and 461 regarding requests for  acceleration .  We will consider a
written request for acceleration of the effective date of the registration statement as confirmation
of the fact that those requesting acceleration are a ware of their respective responsibilities under

Stephen E. Pirnat
ClearSign Combustion Corporation
January 4, 2016
Page 2

 the Securities Act of 1933 and the Securities Exchange Act of 1934 as they relate to the proposed
public offering of the registered securities .

You may contact Geoff Kruczek  at (202) 551 -3641  with any ques tions.

Sincerely,

 /s/ Geoff Kruczek for

Amanda Ravitz
        Assistant Director
        Office of Electronics and Machinery

cc: Kevin Friedmann , Esq.