Specifications

TroubleshootingGuide
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25|Page
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CHECKINGMANIFOLDGASPRESSURE:
1) Ensurethattheunitisnotinoperation.
2) Removethescrewoffthemanifoldport.
3) Connectamanometertothemanifoldportusingatube
(Figure1).Ensurethatthisconnectionissecureenoughto
preventgasleak.
4) Runwatertoactivateitsoperation.Itissuggested
thata
largeamountofflowisdrawninordertoprevent
overheatingduringmaxburn.Ifpresenceofagasleakis
detected,immediatelyshutofftheunitandinspectthe
tube/manifoldconnection;otherwise,proceedontothenextstep.
5) Tocheckthemanifoldgaspressureduringmaximumcombustion,
pressandholdthe“MAX”
buttononthecomputerboard(seeFigure2).Tocheckthemanifoldpressureduring 
minimumcombustion, pressandholdthe“MI N”buttononthecomputerboard.The
desiredpressuresarelistedinthespecificationtableatthebeginningofthismanual.
6) Ifthe
manifoldpressuresdonotmatchupwiththoselisted,adjustthemanifoldpressure(p.
25).
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ADJUSTINGMAN IFOLDPRESSURE: 
Themanifoldgaspressurecanbeadjustedbyfollowingtheprocedures.
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Adjustingthemanifoldpressurecancauseunexpectedcombustionconditionsduring
operation,whichcancauseahealthhazard,damagethe520(T‐H2)or320(T‐H2S),and
orshortenitslifespan.Therefore,changingthemanifoldpressureisnotrecommended
unlessthereareverystrongreasonstodoso(e.g.highelevationinstallations),andwith
theconsultationoftheTechnicalServiceDepartment.

1) Setupthemanometerbyfollowingsteps1
through4onthe“Checkingmanifoldgas
pressure”procedures.
2) Pressandholddownthe“MIN”buttonon
the
computerboard.Whileholdingdown
the“MIN”button,presseitherthe
“INCREASE”or“DECREASE”buttonto
increaseordecreasethemanifoldgas
pressure,respectively(Figure2).Referto
themanometertoverifythatpressurehasbeensettodesiredvalue.
3) Nowpressandholddownthe“MAX”buttononthe
computerboardtochangethe
maximumburnpressure.
4) Repeatedlyadjusttheminimumand maximumpressuresagainuntilbothlevelsarestable
andtherearenomorechangesfromthepreviousiteration.
5) Afterthemanifoldgaspressurehasbeenset,deactivatetheunit(stopallwaterrunning
throughthe
unit),removethemanometertube,andreplacetheportscrew.

WARNING
Increasebutton
Decreasebutton
MAXbutton
MINbutton
Figure26
Figure27