LG Therma V fault CH62

What it means

The heat sink detection temperature is over 85°C, indicating the inverter module (IPM/PFCM/IGBTM) is overheating.

Likely causes

1. Inverter board power module connection status is bad.
2. The fan motor of the outdoor unit operates abnormally.
3. The inverter board of the outdoor unit is defective.
4. Overload operation.
5. Fan locked
6. Obstruction/shield around the heat exchanger
7. Insufficient distance between product and wall
8. Piping condition issues such as pipe bending
9. EEV operation/connection status fault
10. Abnormal refrigerant pressure
11. Compressor restraint
12. Compressor wiring reverse phase loss
13. Short circuit or opening of internal connection line in compressor
14. Compressor winding resistance out of spec
15. Compressor insulation resistance failure
16. Inverter PCB assembly or connector connection fault
17. IGBTM failure
18. Incorrect FCU setting mismatched to actual installation can cause abnormal operation
19. FCU set to 'Use' when not actually installed causes unit to stop unnecessarily
20. FCU set to 'Not use' when FCU is actually installed means Stop temp. is ignored and unit will not stop, risking condensation

Where to start

1. Check if the screw torque of IPM, PFCM is good. If No, tighten the screw of IPM, IGBTM.
2. If screw torque is good (Yes), check if the thermal grease of IPM, IGBTM is normal and if IPM, IGBTM are normal. If No, change the Inverter PCB.
3. If thermal grease and IPM/IGBTM are normal (Yes), recheck power and installation condition.