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XIII Troubleshooting
Thefollowingpagescontaintroubleshootingchartsforuseindiagnosingcontrolproblems.Tousethesecharts,gotothe
boxmarked“Start”atthetopofthechartonpage34or36andfollowtheappropriatepaththoughthechartuntilaboxwith
alistofpossiblecausesisreached.Iftheproblemisknowntobewithintheignitionsystem,godirectlytotheignitionsystem
troubleshootingguidefortheboileronpage38.Inusingthesecharts,thefollowingshouldbekeptinmind:
1) Thesechartsareonlymeanttobeusedbyaprofessionalheatingtechnicianasanaidindiagnosingcontrolproblems.
2) Whereapplicable,followallprecautionsoutlinedintheappropriatelightinginstructionsonpages25-26.
3) Ingeneral,thesechartsassumethattherearenolooseormiswiredelectricalconnections.Beforeusingthesecharts,in-
spectallelectricalconnectionsontheboilertomakesurethattheyaretight.Also,checkthewiringontheboileragainst
theappropriatewiringdiagraminFigures16-17.
4) Thepossiblecausesattheendofeachbranchinthesechartsarenotlistedinorderoflikelihood.AllcontrolsontheBSI
aretestedatleastonceinthemanufacturingprocessandadefectivecontrolorcomponentisgenerallytheleastlikely
cause.Beforereplacingacomponent,trytoruleoutallotherpossiblecauses.
5) Thesetroubleshootingchartsassumethattheventdamperisclosedatthebeginningofthetroubleshootingprocess.With
the120voltsappliedtotheboilerandnocallforheat,thedampershouldgototheclosedposition.Ifitdoesnot,dothe
following:
• Conrmthat120voltsisappliedtotheboilerandthatthereisnocallforheat.
• Makesurethattheswitchonthedamperisinthe“automatic”position.
• Unplugtheharnessfromthedamperandcheckfor24voltsacrosspin#1(blue)andpin#4(yellow).
• Ifvoltageispresent,thedamperisdefectiveorthereisanobstructioninthepathofthedamperblade.
• Ifnovoltageispresent,thereiseitheralooseconnectioninthedamperharnessorthetransformerisdefective.
6) Ifthechartsindicatethatthetransformerisdefective,itispossiblethatthistransformerhasbeendestroyedbyashort
circuitintheboilerwiring.Beforereplacingthetransformer,carefullyinspectalllowvoltagewiringontheboilerfor
placeswhereitistouchingtheframeoftheboilerorwiringontheothersideofthetransformer.
7) IfthechartsindicatethattheR8225relayisdefective,thereisagoodchancethatasecondtransformerispresentinthe
thermostatcircuit,resultingintheapplicationof48voltsacrosstherelaycoil.Inolderbuildings,thistransformermaybe
hiddeninalocationfarfromtheboiler.Ifthissecondtransformerexists,itmustbefoundandremovedbeforetheR8225
isreplaced.
8) Whencheckingvoltageacrossdamperharnesspins,becarefulnottoinsertthemeterprobesintothepins.Doingsomay
damagethepin,resultinginalooseconnectionwhentheharnessisreconnected.