SiBE041025
Troubleshooting
Service Diagnosis
65
4.12 Four Way Valve Abnormality
Remote
Controller
Display
EA
Method of
Malfunction
Detection
The room temperature thermistor, the indoor heat exchanger thermistor, the outdoor
temperature thermistor, and the outdoor heat exchanger thermistor are checked if they function
within their normal ranges in each operation mode.
Malfunction
Decision
Conditions
A following condition continues over 10 minutes after operating for 5 minutes.
Cooling / Dry
(room temp. – indoor heat exchanger temp.) < –5°C
Heating
(indoor heat exchanger temp. – room temp.) < –5°C
Supposed
Causes
Disconnection of four way valve coil
Defective four way valve coil or harness
Defective four way valve
Defective outdoor unit PCB
Defective thermistor
Refrigerant shortage
Water mixed in refrigerant
Defective stop valve