Four Way Valve Abnormality - Daikin F-Series Service Manual

Troubleshooting

4.12 Four Way Valve Abnormality

EA
Remote
Controller
Display
Method of The room temperature thermistor, the indoor unit heat exchanger thermistor, the outdoor
Malfunction temperature thermistor and the outdoor unit heat exchanger thermistor are checked to see if
they function within their normal ranges in the operating mode.
Detection
Malfunction A following condition continues over 1 minute after operating 10 minutes.
Decision
Conditions
Supposed
Causes
108
Cooling / dry operation
(room temp. – indoor heat exchanger temp.) < –5°C
Heating
(indoor unit heat exchanger temp. – room temp.) < –5°C
The system will be shut down if the cooling / heating changeover abnormality occurs 5 times.
Connector in poor contact
Thermistor defective
Outdoor unit PCB defective
Four way valve coil or harness defective
Four way valve defective
Foreign substance mixed in refrigerant
Insufficient gas
Si04-703A
Service Diagnosis