Rheem RTGH-RH10DV - Er:20 High Limit Switch Abnormality

58
Errorcode Meaning Condition
HighLimitSwitchAbnormality
(Manualrestore)
WhentheHighLimitSwitch
temperatureisoverheated,error
code20willappear.
Failureevent
AnEr.20willdisplayifthetemperatureoftheheatingwaterexitingtheprimaryheatexchangerexceeds
theHighLimitSwitch'sdefaultsettings.Combustionwillstopandthefanwillcontinuetorunforpost-
purge.
Checkpoint
①InspecttheHighLimitSwitchwhenerrorcodeappearseven
iftheheatingsupplytemperatureisnottoohigh.
②Checkconnectorandifnoproblem,measureHighLimit
Switchlocatedatheatexchangeroutletandreplacewhenthe
multi-metervalueshows'0L'.(Normalvalueis'0~0.5Ω'.)
(CN11:red⑧,⑯)
③Checkthecirculationpumpspeedsettingasspeed.
Chapter4Troubleshooting
HighLimitSwitch
(203℉/95℃)
1
2
3
4
5
6
9
10
11
12 13
7
14 15
8
16