Lennox MPB018S4M - Page 139

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Error Code: F3
Description: Compressordischargetemperaturesensorerror
General Note: Whenthecompressordischargetemperature(T5)ismorethan115°Cfor10seconds,thecompressorwillstopandrestart
tillT5islessthan90°C.
Temperatureprotectionofcompressor.
Checkwhetherthecompressordischargetemp.is
morethan115°C?
No
Checkwhethertheconnectionisrightbetweencom-
pressordischargetemp.sensorandPCBaccordingto
wiringdiagrams?
Checkwhetherthe
refrigerantisleak.
Yes
Stopleakingandadd
refrigerant.
Yes
No
Correctthewiringcon-
nection.
No
Yes
Measuretheresistancevalueofcompressordis-
chargetemp.sensor.Ifthevalueisnotnormalis
normalrefertotheAppendix2?
Replacethecompressor
dischargetemp.sensor.
No
Yes
ReplaceoutdoormainPCB.
No
Replacehighpressurevalveassy.