<SEC-DOCUMENT>0001144204-19-033823.txt : 20190703
<SEC-HEADER>0001144204-19-033823.hdr.sgml : 20190703
<ACCEPTANCE-DATETIME>20190703172301
ACCESSION NUMBER:		0001144204-19-033823
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20190630
FILED AS OF DATE:		20190703
DATE AS OF CHANGE:		20190703

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			HOFFMAN Robert Thurston Sr
		CENTRAL INDEX KEY:			0001748409

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-35521
		FILM NUMBER:		19942628

	MAIL ADDRESS:	
		STREET 1:		119 WARREN AVENUE
		CITY:			SPRING LAKE
		STATE:			NJ
		ZIP:			07762

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			CLEARSIGN COMBUSTION CORP
		CENTRAL INDEX KEY:			0001434524
		STANDARD INDUSTRIAL CLASSIFICATION:	INDUSTRIAL INSTRUMENTS FOR MEASUREMENT, DISPLAY, AND CONTROL [3823]
		IRS NUMBER:				000000000
		STATE OF INCORPORATION:			WA
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		12870 INTERURBAN AVENUE SOUTH
		CITY:			SEATTLE
		STATE:			WA
		ZIP:			98168
		BUSINESS PHONE:		(206) 673-4848

	MAIL ADDRESS:	
		STREET 1:		12870 INTERURBAN AVENUE SOUTH
		CITY:			SEATTLE
		STATE:			WA
		ZIP:			98168
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>tv524822_4.xml
<DESCRIPTION>OWNERSHIP DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2019-06-30</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001434524</issuerCik>
        <issuerName>CLEARSIGN COMBUSTION CORP</issuerName>
        <issuerTradingSymbol>CLIR</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001748409</rptOwnerCik>
            <rptOwnerName>HOFFMAN Robert Thurston Sr</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>119 WARREN AVENUE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>SPRING LAKE</rptOwnerCity>
            <rptOwnerState>NJ</rptOwnerState>
            <rptOwnerZipCode>07762</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Option to Purchase Common Stock</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>1.00</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2019-06-30</value>
                <footnoteId id="F1"/>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>21625</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0.00</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <value>2019-06-30</value>
            </exerciseDate>
            <expirationDate>
                <value>2029-04-01</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>21625</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>43250</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">On May 9, 2019 the Issuer's board of directors approved compensation to be paid to the Issuer's non-executive directors for services provided to the Issuer during 2019.  The reporting person is an non-executive director.  As compensation for their services, each non-executive director was awarded options for shares of common stock having an exercise price of $1.00.  The total number of option shares awarded was based on the services provided by the director.  These services include Board participation, committee participation, committee chair responsibilites and lead director responsibilities, if any. The right to purchase the common stock is earned in quarterly increments.  The option was issued from the Company's 2011 Equity Incentive Plan.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Robert T. Hoffman</signatureName>
        <signatureDate>2019-07-03</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
