Specifications

ManualsBrandsA.O. Smith ManualsHome building and DecorT-H2-OS

TroubleshootingGuide

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24|Page

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3) Securelyscrewthefilterbackintoplace.Hand‐tightenonly.

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CHECKINGFORACROSSCONNECTION: 

1) Turnoffcoldwatersupply.

2) Turnonallhotwaterfixtures.

a. Thewatershouldeventuallycompletelydrain.

b. Ifwatercontinuestorun,thefixturesandplumbingsystemneedstobechecked.

c. Coldwatercrossconnectionsmayberelatedtoarecirculationpumpapplication,a

badcheck

valve,ormissingcheckvalveintheapplication.

CHECKFOR REVERSE C ONNECTION:

1) Closecoldwatersupplyattheinlet.

2) Openthepressure‐reliefvalve;itshouldbeinstalledonthehotsideoutletoftheunit.

3) Ifwatercontinuestorun throughthepressure‐reliefvalve,thesystemhasareverse

connection.

CHECKGA SSUPPLYPRESSURE:

1) Closethemanualgasinletshutoff

valveonthegassupplyline.

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2) Openafaucet.Theunitshouldturn

onandthegasinthepipelineshould

purge.Leavethefaucetontokeep

theunitrunninguntilitshutsdown

duetolackofgas,andthenshutthe

faucetoff.Ignoreanyerrorcodes

thatmayoccurat

thistime.

3) Removethescrewforthepressure

portlocatedonthegasinletshown

ontheright.

4) Connectamanometertothepressureport.

5) Slowlyre‐openthemanualgasvalve.Checktoseethattherearenogasleaks.

6) Opensomeofthefixturesthat

usethehighestflowratetoturnontheunit.

7) Checktheinletgaspressure.Appropriatepressuresareasfollows:

a. Naturalgas: 5–10.5inchesW.C.

b. Propane: 8–14.0inchesW.C.

PURGETHEGA SLINEOFAIR:

1) Theunitshouldnotberunningduringthisprocedure.Turnoffpowertotheunit.

2) Turnthegasvalvetotheoffposition(perpendiculartothegasline).

3) Loosenthegaslineontheunitsideofthegasvalve(ataflarefittingorunion).

4) Next

openthegasvalveveryslightlyuntilyoucansmellgasbywaftingtheairtowardsyour

nose.Thismeansanyairpreviouslyinthegaslinehasbeenremovedandonlygasremains.

5) Turngasbackoffandre‐tightengasline.

6) Turngasbackonand

checkforleaks.Spraywater&dishsoapmixtureontofittings.No

bubblesmeanstherearenoleaks.

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Figure25