A.O. Smith 310 - TROUBLESHOOTING - GENERAL PROBLEMS; THE WATER IS NOT HOT ENOUGH; THE WATER IS TOO HOT

TroubleshootingGuide
8|Page

5.2TROUBLESHOOTING‐GENERALPROBLEMS
ProceedtotheErrorCodessectionifanerrorcodeisidentified.Forothercommonproblemsthatdo
notinvolveanerrorcode,seeifthefollowingitemshelp:
 Thewaterisnothotenough.
 Thewateristoohot.
 Temperaturefluctuateswhenafixtureisopened. 

Unitdoesnotignitewhenwatergoesthroughit.
 Ittakesalongtimetogethotwateratthefixtures.
 Thefanmotorisstillspinningafteroperationhasstopped.
 Abnormalsoundscomefromtheunit.
 Lossofpressureatallsinkswhenthedishwasher
fills.
 Unithaspower,gas,andwaterbutdoesnotturnon.
 MultipleHeaterSetup(Easy‐Link)
THEWATERISNOTHOTENOUGH
• Comparetheflowandtemperatureatthepressurereliefvalve.
o IfthetemperatureandflowratearecorrectatthePRVthentheproblemresidesinthe
plumbingline,notinthetanklessunit.Checkforacrossconnectionorotherwaterline
problems
• Testthehotwater
temperaturewithahandheldthermometertomeasurehowfaroffthewater
temperatureisfromthesettemperature.
o Thesettemperaturemaybesettoolow.Thetemperaturecanbechangedwiththe
pushbuttonsonthePCBorbytheremotetemperaturecontroller,ifoneisinstalled.
• Check
forcrossplumbingbetweencoldwaterlinesandhotwaterlines.SeetheProcedures
section(p.21)forinstructions.
• Unitmaybehardwaterscaled.Thescaleactsasaninsulatorpreventingtheheatexchanger
fromtransferringheattothewater.ContactaTakagiServiceAgent.
• Theunitmay
notbereceivingenoughgas.
o Thegassupplyvalvemaynotbefullyopen.
o Thegaslinemaybesizedimproperly.
o Thegassupplypressuremaybetoolow.Thismay becausedbyamalfunctioninggas
supplyregulator,sochecktoseeifyourregulatoris
workingproperly.
• Checktoseethatacheckvalveisinstalledbetweenthepumpdischargeandtheconnectionto
thecoldwatersupply.Inspectthecheckvalveforproperoperation.Ifthereisn’toneinstalled,
orifitismalfunctioning,coldwatermaybeback‐feedingintothesystem.
•
Double‐checkfora101errorcode.A101errorcodewillreducetheamountofgasinputinto
theheater.
• Outputtemperaturewillbeaffectedifairflowisimpeded.
o Checkconstructiondustanddebrisinventing,suchasdrywall.
o Ifthereisdustinside
thecabinet,therewillalsobedustinsidetheburnerandheat
exchanger.Seetheprocedureforcleaningtheburner(p.26).

THEWATERISTOOHOT
• Thesettemperaturemaybesettoohigh.Thetemperaturecanbechangedwithdipswitcheson
thePCBorbytheremotetemperaturecontroller,ifoneisinstalled.