LG Air Conditioner Error Code CH16

CH16 on an LG air conditioner means the unit has received a fire alarm signal and has shut down as a safety measure. This can result from an actual fire or smoke condition, a triggered building fire alarm system, a faulty sensor, or a wiring fault. The unit will not operate again until the underlying cause is resolved and the error is cleared.

A simple power reset may temporarily clear the CH16 code, but the error will return if the underlying cause is still present. If the fire alarm input is still active, whether from a connected alarm system, a faulty sensor, or a wiring issue, the unit will shut down again immediately or shortly after restart. The root cause must be identified and corrected before a reset will be effective long term.

Repair costs vary widely depending on the cause. If the issue is a building alarm system reset or a wiring connection fix, costs may be minimal, covering only a service call fee in the range of $75 to $150. Replacing a faulty fire or smoke sensor can add $50 to $200 in parts. A control board replacement is the most expensive scenario, typically ranging from $200 to $600 or more depending on the model and labor rates.

Treat CH16 as a potential safety alert and take it seriously. First verify there is no actual fire or smoke present in the building before assuming it is a false alarm. If you are unsure of the cause, evacuate and contact emergency services as a precaution. Only after confirming the area is safe should you begin diagnosing the error.

If the unit is connected to a building fire alarm system, you may be able to resolve CH16 by resetting the building alarm panel after verifying the space is safe. However, diagnosing faulty sensors, wiring faults, or control board issues requires technical knowledge and appropriate test equipment. Given the safety-critical nature of this error, professional service is strongly recommended if the cause is not immediately obvious.