Willis WST12MC16S Service Manual page 44

Malfunction diagnosis of startup failure
Main detection points:
Is wiring of compressor correct.
Is the stop time of compressor enough?
Is compressor damaged?
Malfunction diagnosis process:
60
Energize the
unit and start it
Check connecting state
Indoor unit
Y
of indoor
display F1/F2
temperature sensor
N
I ndoor unit
display F4/F5
Y
Check connect i ng state
of outdoor
temperature sensor
Adjust
Reliable
N
connected? connecting state
Y
Replace
N
Remove error?
temperature sensor?
Remove error?
N
Y
Y
Replace parts
of outdoor
electric box
reliable
N
connected?
Adjust connecting stat
Y
Replace
Remove error?
temperature sensor
N
Remove error?
N
Replace main
Y
board of indoor unit
Finish
Troubleshooting