Panasonic WH-MDF09C3E8 Service Manual page 98

16.5.20 Compressor Overheating (F20)
Malfunction Decision Conditions:
During operation of heating, when temperature above 112°C is detected by the compressor tank temperature
sensor.
Malfunction Caused:
1 Faulty compressor tank temperature sensor.
2 2/3 way valve closed.
3 Refrigerant shortage (refrigerant leakage).
4 Clogged expansion valve or strainer.
5 Faulty outdoor unit PCB (main).
6 Faulty compressor.
Abnormality Judgment:
Continue 4 times in 30 minutes.
98