LG Air Conditioner Error Code CH02

CH02 on an LG air conditioner indicates an indoor inlet pipe sensor error. The fault can be caused by a loose connector at the indoor PCB, a sensor that has failed in an open or short condition, or a defective PCB. The unit stops normal operation when this code appears to protect the system from running with inaccurate temperature data.

It is not recommended to continue operating the unit while CH02 is active. The inlet pipe sensor provides critical temperature data that the control board uses to prevent issues like evaporator freezing. Running the system without accurate sensor input could lead to inefficient operation or component damage over time.

A power reset may temporarily clear the CH02 code, but the error will return if the underlying fault is still present. The sensor, wiring, and PCB connector need to be inspected and tested to resolve the root cause. A reset alone is not a fix and should only be used as part of the diagnostic process after addressing any identified issues.

Checking and reseating the sensor connector is a straightforward task that a knowledgeable DIYer can perform after powering down the unit. Using a multimeter to test sensor resistance (target 5 kilohms at 25 degrees Celsius) or voltage (target 2.2 volts DC when connected) is also manageable with basic electrical knowledge. However, if the PCB itself is faulty, replacement and proper calibration should be handled by a qualified technician.

Repair costs vary depending on the actual fault. Replacing a thermistor sensor typically costs between 20 and 80 dollars for the part, with labor adding 75 to 150 dollars depending on your location and service provider. If the indoor PCB requires replacement, total costs including parts and labor can range from 200 to 500 dollars or more.