Panasonic Aquarea T-CAP R32 fault H42

What it means

During operation of heating and after 5 minutes compressor ON, when outdoor pipe temperature below -37°C or above 26°C is detected by the outdoor pipe temperature sensor.

Likely causes

1. Clogged expansion valve or strainer
2. Insufficient refrigerant
3. Refrigerant shortage (refrigerant leakage)

Where to start

1. Check expansion valve/strainer for blockage
2. Check refrigerant charge
3. If fan motor normal, check for gas leakage. Is the oil oozing out from the 2/3 way valve? If Yes, repair the pipe flare or union nuts, reclaim and recharge refrigerant.