LG Air Conditioner Error Code CH46

CH46 on an LG air conditioner indicates a suction pipe temperature sensor error. The sensor monitoring return gas temperature on the refrigerant suction line has either an open circuit or a short circuit, producing an abnormal signal. The unit shuts down to protect the compressor until the fault is resolved.

No, you should not continue operating the unit with an active CH46 fault. The suction pipe temperature sensor helps protect the compressor from operating under unsafe refrigerant conditions. Running the system without a valid sensor signal could lead to compressor damage, which is a significantly more expensive repair than replacing the sensor.

Resetting the unit by cycling the power may temporarily clear the code, but CH46 will return if the underlying sensor or wiring fault is still present. A reset alone does not repair a failed thermistor, damaged wire, or corroded connector. The fault must be diagnosed and the defective component repaired or replaced for the error to be permanently cleared.

Some basic checks, such as inspecting the sensor wiring for visible damage or reseating a loose connector, can be performed without special tools. However, accurate diagnosis requires a multimeter to test thermistor resistance and knowledge of the expected resistance values for that sensor. Refrigerant system work requires certification, but the sensor itself does not involve opening the refrigerant circuit, making sensor replacement a feasible DIY repair for experienced technicians or knowledgeable homeowners comfortable with disassembling the indoor or outdoor unit.

If the repair only requires a new suction pipe thermistor, parts and labor typically range from around $80 to $200 depending on the unit model and local labor rates. If the wiring harness needs repair or replacement, costs may be similar. A control board replacement, if the board's sensor input circuit has failed, can range from $200 to $500 or more including labor.