<SEC-DOCUMENT>0001179110-19-000629.txt : 20190109
<SEC-HEADER>0001179110-19-000629.hdr.sgml : 20190109
<ACCEPTANCE-DATETIME>20190109180647
ACCESSION NUMBER:		0001179110-19-000629
CONFORMED SUBMISSION TYPE:	3
PUBLIC DOCUMENT COUNT:		2
CONFORMED PERIOD OF REPORT:	20190101
FILED AS OF DATE:		20190109
DATE AS OF CHANGE:		20190109

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Young Terrence Andrew
		CENTRAL INDEX KEY:			0001764103

	FILING VALUES:
		FORM TYPE:		3
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-13011
		FILM NUMBER:		19518963

	MAIL ADDRESS:	
		STREET 1:		675 BERING DRIVE SUITE 400
		CITY:			HOUSTON
		STATE:			TX
		ZIP:			77057

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			COMFORT SYSTEMS USA INC
		CENTRAL INDEX KEY:			0001035983
		STANDARD INDUSTRIAL CLASSIFICATION:	ELECTRICAL WORK [1731]
		IRS NUMBER:				760526487
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		675 BERING DRIVE
		STREET 2:		SUITE 400
		CITY:			HOUSTON
		STATE:			TX
		ZIP:			77057
		BUSINESS PHONE:		7138309600

	MAIL ADDRESS:	
		STREET 1:		675 BERING DRIVE
		STREET 2:		SUITE 400
		CITY:			HOUSTON
		STATE:			TX
		ZIP:			77057
</SEC-HEADER>
<DOCUMENT>
<TYPE>3
<SEQUENCE>1
<FILENAME>edgar.xml
<DESCRIPTION>FORM 3 -
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0206</schemaVersion>

    <documentType>3</documentType>

    <periodOfReport>2019-01-01</periodOfReport>

    <noSecuritiesOwned>0</noSecuritiesOwned>

    <issuer>
        <issuerCik>0001035983</issuerCik>
        <issuerName>COMFORT SYSTEMS USA INC</issuerName>
        <issuerTradingSymbol>FIX</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001764103</rptOwnerCik>
            <rptOwnerName>Young Terrence Andrew</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>675 BERING DRIVE, SUITE 400</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>HOUSTON</rptOwnerCity>
            <rptOwnerState>TX</rptOwnerState>
            <rptOwnerZipCode>77057</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Senior Vice President Service</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>300</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes></footnotes>

    <ownerSignature>
        <signatureName>/s/ Laura F. Howell, by power of attorney</signatureName>
        <signatureDate>2019-01-09</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
<DOCUMENT>
<TYPE>EX-24.EX-24 (POA)
<SEQUENCE>2
<FILENAME>ex24young.txt
<DESCRIPTION>EXHIBIT 24 - POWER OF ATTORNEY
<TEXT>
Exhibit 24

Limited Power of Attorney for Section 16 Reporting Obligations

The undersigned hereby makes, constitutes, and appoints Laura F. Howell,
acting individually, as the undersigned's true and lawful attorney-in-
fact, with full power and authority as hereinafter described on behalf of
and in the name, place, and stead of the undersigned to:

     1) prepare, execute, acknowledge, deliver, and file Forms 3, 4, and
5 (including any amendments thereto) with respect to the securities of
Comfort Systems USA, Inc., a Delaware corporation (the "Company"), with
the United States Securities and Exchange Commission, any national
securities exchanges, and the Company, as considered necessary or
advisable under Section 16(a) of the Securities Exchange Act of 1934 and
the rules and regulations promulgated thereunder, as amended from time to
time (the "Exchange Act");

     2) seek or obtain, as the undersigned's representative and on the
undersigned's behalf, information on transactions in the Company's
securities from any third party, including brokers, employee benefit plan
administrators, and trustees, and the undersigned hereby authorizes any
such person to release any such information to the attorney-in-fact and
approves and ratifies any such release of information; and

     3) perform any and all other acts that, in the discretion of such
attorney-in-fact, are necessary or desirable for and on behalf of the
undersigned in connection with the foregoing.

The undersigned acknowledges that:

     1)this Power of Attorney authorizes, but does not require, such
attorney-in-fact to act in his or her discretion on information provided
to such attorney-in-fact without independent verification of such
information;

     2)any documents prepared and/or executed by such attorney-in-fact on
behalf of the undersigned pursuant to this Power of Attorney will be in
such form and will contain such information and disclosure as such
attorney-in-fact, in his or her discretion, deems necessary or desirable;
neither the Company nor such attorney-in-fact assumes (i) any liability
for the undersigned's responsibility to comply with the requirement of
the Exchange Act, (ii) any liability of the undersigned for any failure
to comply with such requirements, or (iii) any obligation or liability of
the undersigned for profit disgorgement under Section 16(b) of the
Exchange Act; and
     3)this Power of Attorney does not relieve the undersigned from
responsibility for compliance with the undersigned's obligations under
the Exchange Act, including without limitation the reporting requirements
under Section 16 of the Exchange Act.
     4)The undersigned hereby gives and grants the foregoing attorney-in-
fact full power and authority to do and perform all and every act and
thing whatsoever requisite, necessary, or appropriate to be done in and
about the foregoing matters as fully to all intents and purposes as the
undersigned might or could do if present, hereby ratifying all that such
attorney-in-fact of, for, or on behalf of the undersigned, shall lawfully
do or cause to be done by virtue of this Limited Power of Attorney.
This Power of Attorney shall remain in full force and effect until the
undersigned is no longer required to file Forms 3, 4, and 5 with respect
to the undersigned's holdings of and transactions in securities issued by
the Company, unless earlier revoked by the undersigned in a signed
writing delivered to the foregoing attorney-in-fact.
IN WITNESS WHEREOF, the undersigned has caused this Power of Attorney to
be executed in Harris County, Texas as of this _2nd__ date of January,
2019.

_/s/ Terrence A. Young_____________________________________
Terrence A. Young



</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
