A.O. Smith 310 - UNIT DOES NOT IGNITE WHEN WATER GOES THROUGH IT

TroubleshootingGuide
10|Page
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UNITDOESNOTIGNITEWHENWATERGOESTHROUGHIT
• Istheflowrateover0.75gpm?Seeiftheunitinitiateswhenyouincreasedemandofwater
beingdrawnthroughtheunit(e.g.ope ningupmorehotfixtures).
• Checkthatthegaslineisopenandispurgedofair(p.22).
• Checkthatthefilteron
thecoldwaterinletisclean(p.21).
• Checkforreverseconnectionandcrossconnection(p.21).
• Problemswithrecirculationsystem
o Seethatacheckvalveisinstalledbetweenthepumpdischargeandtheconnectionto
thecoldwatersupply.Amalfunctioningormissingcheckvalvewill
causecoldwaterto
back‐feedintothesystem.
•
Ifyouusetheremotecontroller,istheremotepowerbuttonturnedon? 
• ChecktoseeiftheComputerboardisr eceivingpow er.Thiscanbeverifiedbyobservingthe
computerboardredLED.
o Ifitisnotlit,thecomputerboardisnotbeingpowered.Checktosee
iftheON/OFF
switchbelowthefuseboxissettotheonposition,orifthefuseinthefuseboxis
blown.
• Ifthefandoesnotinitiateatallanditisverifiedthattheunitispowered(seeabove),theflow
sensormaynotbeworking
properly.Checktheflowsensorforproperimpellerfunctionality.
ITTAKE SALONGTIME TOGETHOTWATERATTHEFIXTURES
• Thetimeittakestodeliverhotwatertoyourfixturesdependsonthelengthofpipingbetween
thetwo.Thelongerthedistance orthebiggerthepipes,thelongeritwilltaketogethotwater.
Ifthisisthecaseandyouwouldliketoreceivehot
watertoyourfixturesquicker,youmaywant
toconsiderahotwaterrecirculationsystem.
• Problemswiththerecirculationsystem.
o Seethatacheckvalveisinstalledbetweenthepumpdischargeandtheconnectionto
thecoldwatersupply.Amalfunctioningormissingcheckvalvewillcausecold
waterto
back‐feedintothesystem.
THEFANMOTORISSTILLSPINNINGAFTEROPERATIONHASSTOPPED
• Thisisnormal.Afteroperationhasstopped,thefanmotorkeepsrunning
from5to50secondsinordertore‐ignitequickly,aswellaspurgeallthe
exhaustgasoutoftheflue.
ABNORMALSO UNDSCOMEFROMTHEUNIT
• Checkthefanfordebris.
• ContacttheTechnicalServiceDepartment.
LOSSOF PR ESSUREATALLSINKSDURINGCOMMERCIALDI SHWASHERFILLS
• Verifythecapacityoftheheater(s)versustheGPMdemandofthedishwasher.
• Checkthesizeofthesupplylinestothedishwasher.
• Lookforawaterregulatoronthedishwasher.Checkthedishwasherratingplatetoconfirmthe
recommendedsupplywaterpressure.
• Unitmaybehard
waterscaled.Scalecanreducepressureandflowofwaterthroughtheunit;
thiscanoccurasquicklyasafewmonths.
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Figure3