A.O. Smith 110 - 5. TROUBLESHOOTING; 5.1 PRELIMINARY CHECKLIST

TroubleshootingGuide
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5.TROUBLESHOOTING
5.1PRELIMINARYCHECKLIST
Checkallofthesebasicitemsbeforeproceedingontoanyothersection:
• GAS/WATER/ELECTRIC:
o Thegassupplyvalveshouldbefullyopen.
o Verifythecorrectgastypeisbeingused,NGorLP.
o Thewatersupplyvalveshouldbefullyopen.
o Theunitshouldbeconnected
toa120VAC60Hzpowersupply.Thiscanbeverifiedby
observingthecomputerboard3‐digitLEDdisplay.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.
• REMOTE:Ifyouareusingaremotecontroller,theremote’spowerbuttonmustbeturnedon.
• HIGHALTITUDE:Isyourlocationatanaltitudeofover3000feet?Thismaycausealack ofair.
Seethehighaltitude
procedureintheTroubleshootingProceduressection.
• HARDWATER:Whatisthehardnessofthewater?Asoftenerisalwaysrecommended,butif
thewaterisabove7grainsofhardnessor70‐140ppm,onemustbeinstalled.Ifthereisno
watersoftenerinstalled,existinginstallationswillgraduallyaccumulate
scalebuilduponthe
heatexchangerandcausealeak.Heatexchangerfailuresdotohardwaterscalearenot
coveredunderthewarranty.
• NEWINSTALLATIONS:Isthisinstallationafewyearsoldorbrandnew?
o Aunitthathasworkedproperlyforawhilebutisnowstruggling
mayhavebecome
scaleduporcontainsadirtyburner.
o Anewinstallationmostlikelyisinstalledorplumbedincorrectly.
• EXTERNALPROBLEM:Testwhethertheproblemiswithintheunitorexternaltotheunit(i.e.in
theplumbingsystem)byattemptingtorunhotwaterlocallythrough
thepressurereliefvalve
(PRV).
o Doestheheaterigniteandremainrunningproperly? Ordoestheheatershutdowninto
anerrorcode?IfitrunsfinethroughthePRVtheplumbingsystemisatfault.
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NEXTSTEP:Finally,checktoseeiftheunithasanerrorcode.
Theerrorcodewillbedisplayedonthe
sevensegmentLEDonthebottomleftofthecomputerboard.Seefigures4and5.
• Ifitisdisplayinganerrorcode,proceedtotheErrorCodessection(p.12).
• Ifthereisnoerrorcode,proceedtothe
GeneralProblemssection(p.8).
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