Panasonic WH-MXC16J9E8 Service Manual page 175

17.5.31 Compressor Overheating (F20)
Malfunction Decision Conditions:
During operation of cooling and heating, when temperature above 117°C is detected by the outdoor discharge
pipe temperature sensor.
Malfunction Caused:
1 Faulty outdoor discharge pipe 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 20 minutes.
Troubleshooting:
Check the outdoor discharge pipe
temperature sensor.
Does it conform to the
sensor characteristic chart?
Yes
Check the 2/3 way valve.
Is the 2/3 way valve closed?
No
Check for gas leakage.
Is the oil oozing out from
the 2/3 way valve?
No
Caution
No
Replace the outdoor discharge
pipe temperature sensor.
Yes
Open the 2/3 way valve.
- Repair the pipe flare or
Yes
union nuts.
- Reclaim and recharge
refrigerant.
For safety reason and to prevent component breakdown,
always switch off the power before remove and connect the component.
Check for clogged expansion
valve or strainer.
Is the expansion valve or
strainer clogged (ice formed)?
No
Reclaim and recharge for a
specified amount of fresh refrigerant.
Is abnormality happened
again?
No
175
- Repair expansion valve
Yes
and/or strainer.
- Reclaim and recharge
refrigerant.
- Replace the outdoor unit
Yes
PCB (main).
- Replace the compressor.
Procedure complete.