LG Air Conditioner Error Code CH35

CH35 indicates that the low pressure sensor is reading a suction-side refrigerant pressure below the acceptable operating range. LG systems trigger this fault to protect the compressor from running under low-charge or no-charge conditions. Common triggers include blocked airflow, a closed service valve, or a refrigerant leak. The unit will typically shut down until the fault condition is corrected.

You should not continue operating the unit with an active CH35 fault. Running the compressor with insufficient refrigerant pressure can cause compressor overheating and permanent damage. The system is designed to shut down on this fault for exactly that reason. Address the root cause before restarting the unit.

A power reset may temporarily clear the CH35 code, but the fault will return if the underlying cause has not been fixed. If the suction pressure remains below the threshold when the unit restarts, the system will detect the fault again and shut down. Always resolve the root cause, such as clearing airflow restrictions or correcting refrigerant charge, before relying on a reset to restore normal operation.

Some causes of CH35 can be resolved without professional help. Cleaning or replacing a clogged air filter, clearing debris from the outdoor unit, and verifying that service valves are fully open are all tasks a homeowner can perform. However, if the issue is a refrigerant leak or low charge, EPA 608 certification is required to handle refrigerants, and that work must be done by a licensed technician.

Repair costs depend entirely on the root cause. Clearing a blocked filter or coil costs nothing beyond time. If a refrigerant leak is involved, repair costs typically range from $150 to $600 or more depending on leak location, refrigerant type, and the amount of refrigerant needed to recharge the system. A sensor replacement, if required, generally falls in the $75 to $250 range including labor.