<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2015-02-04</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001506401</issuerCik>
        <issuerName>InfraREIT, Inc.</issuerName>
        <issuerTradingSymbol>HIFR</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001630928</rptOwnerCik>
            <rptOwnerName>Nelson Benjamin D.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>1807 ROSS AVENUE, 4TH FLOOR</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>DALLAS</rptOwnerCity>
            <rptOwnerState>TX</rptOwnerState>
            <rptOwnerZipCode>75201</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>SVP &amp; General Counsel</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Class A common stock, $0.01 par value per share</value>
                <footnoteId id="F1"/>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F1"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2015-02-04</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>929</value>
                </transactionShares>
                <transactionPricePerShare>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F1"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>common stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>929</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>929</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
        <derivativeTransaction>
            <securityTitle>
                <value>Class C common stock, $0.01 par value per share</value>
                <footnoteId id="F2"/>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F2"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2015-02-04</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>470</value>
                </transactionShares>
                <transactionPricePerShare>
                    <footnoteId id="F2"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F2"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F2"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>common stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>470</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>470</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">As of the effective time (&quot;Effective Time&quot;) of the transactions contemplated by the Merger and Transaction Agreement (the &quot;Merger Agreement&quot;), by and among InfraREIT, Inc., InfraREIT Partners, LP and InfraREIT, L.L.C., pursuant to the terms of the Merger Agreement, each common share of InfraREIT, L.L.C. held by the reporting person was converted into the right to receive one share of Class A common stock of InfraREIT, Inc. (&quot;Class A Common Stock&quot;).  Pursuant to the amended and restated charter of InfraREIT, Inc., on or around the 32nd day following the completion of InfraREIT Inc.'s initial public offering, a number of the shares of Class A Common Stock held by the reporting person may be cancelled if it is determined that Hunt-InfraREIT, L.L.C. is owed additional carry pursuant to the terms of the partnership agreement of InfraREIT Partners, LP.  Following any such cancellation, each remaining share of Class A Common Stock will convert into one share of common stock of InfraREIT, Inc.</footnote>
        <footnote id="F2">As of the Effective Time, pursuant to the terms of the Merger Agreement, each Class C common share of InfraREIT, L.L.C. held by the reporting person was converted into the right to receive one share of Class C common stock of InfraREIT, Inc. (&quot;Class C Common Stock&quot;).  Pursuant to the amended and restated charter of InfraREIT, Inc., on or around the 32nd day following the completion of InfraREIT Inc.'s initial public offering, a number of the shares of Class C Common Stock held by the reporting person may be cancelled if it is determined that Hunt-InfraREIT, L.L.C. is owed additional carry pursuant to the terms of the partnership agreement of InfraREIT Partners, LP.  Following any such cancellation, each remaining share of Class C Common Stock will convert into one share of common stock of InfraREIT, Inc.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/  Gregory S. Imhoff as Attorney-In-Fact for Benjamin D. Nelson</signatureName>
        <signatureDate>2015-02-06</signatureDate>
    </ownerSignature>
</ownershipDocument>
