LG Therma V fault CH24

What it means

Compressor stop caused by operation of the high pressure switch, indicating excessive refrigerant discharge pressure detected by the system.

Likely causes

1. High pressure switch failure
2. Fan failure of outdoor unit
3. Deformation due to breakage of refrigerant pipe
4. Refrigerant overcharge
5. Incorrect pipe length or amount of refrigerant
6. Abnormal sound in outdoor unit (compressor, fan, or other components)
7. Failure of circuit board (fan control board or main board)
8. Fan locked
9. Abnormal refrigerant pressure

Where to start

1. Use a multimeter probe to check continuity/short across the pressure switch connector pins as shown in the reference photo.
2. If high voltage switch terminal is not shorted, replace the high pressure switch.
3. If reproduced upon restart, check if the high pressure on the manifold gauge is over 2500 kPa. If not, replace Inv PCB (Outdoor).