Four Way Valve Abnormality - Daikin FTXN25KEV1B Service Manual

SiBE041102_A

4.12 Four Way Valve Abnormality

EA
Remote
Controller
Display
Method of The room temperature thermistor, the indoor heat exchanger thermistor, the outdoor
Malfunction temperature thermistor, and the outdoor heat exchanger thermistor are checked if they function
within their normal ranges in each operation mode.
Detection
Malfunction A following condition continues over 10 minutes after operating for 5 minutes.
Decision
Conditions
Supposed
Causes
Service Diagnosis
Cooling / Dry
(room thermistor temp. – indoor heat exchanger temp.) < –5°C
Heating
(indoor heat exchanger temp. – room thermistor temp.) < –5°C
If the error repeats, the system is shut down.
Reset condition: Continuous run for about 60 minutes without any other error
Disconnection of four way valve coil
Defective four way valve, coil, or harness
Defective outdoor unit PCB
Defective thermistor
Refrigerant shortage
Water mixed in refrigerant
Defective stop valve
Troubleshooting
67