LG Heat Pump Error Code CH02

CH02 indicates a problem with the refrigerant inlet side temperature sensor. The control board is receiving a signal from this sensor that is outside of normal operating parameters. This sensor should measure approximately 5k ohms resistance at 25 degrees Celsius when unplugged, or approximately 2.5Vdc when connected and powered. The system flags CH02 when those values are not met.

Continued operation with a CH02 error is not recommended. The refrigerant inlet sensor provides critical data the control board uses to protect the compressor and manage refrigerant flow. Running the system without reliable sensor input can lead to improper operation, reduced efficiency, or compressor damage over time.

Repair costs vary depending on the root cause. A replacement refrigerant inlet temperature sensor typically costs between 15 and 60 dollars for the part alone. If a service technician is needed for diagnosis and replacement, total costs including labor can range from 100 to 350 dollars or more. PCB replacement, if required, will increase costs significantly.

A knowledgeable DIYer can perform the initial checks, including inspecting the sensor connector for proper seating and measuring resistance at the sensor with a multimeter. If the connector is secure and the resistance reads near 5k ohms at 25 degrees Celsius, the wiring or PCB may be at fault. Sensor replacement is relatively straightforward, but any work involving refrigerant circuits or PCB replacement should be handled by a qualified technician.

A reset may temporarily clear the code, but if the underlying sensor, wiring, or connector problem is still present, CH02 will return. Resetting without diagnosis and repair is not a lasting solution and may delay finding the actual fault.