LG Air Conditioner Error Code CH24

CH24 means the high pressure switch in the refrigerant circuit has tripped 5 or more times within a single hour. The switch is a safety device that opens when discharge-side refrigerant pressure climbs too high, shutting down the compressor to prevent damage. The code indicates a persistent high-pressure condition that needs to be diagnosed and corrected before the unit will operate normally. Common causes include a dirty outdoor coil, a failed outdoor fan motor, or an overcharged refrigerant system.

No. CH24 indicates the system is repeatedly exceeding safe refrigerant pressure limits. Continuing to operate the unit under these conditions risks damaging the compressor, bursting refrigerant lines, or causing component failures that are significantly more expensive to repair. The system should remain off until the cause of the high-pressure condition is identified and corrected.

Repair costs depend entirely on the root cause. Coil cleaning by a technician typically runs in the range of $75 to $200. Replacing an outdoor fan motor or capacitor can cost anywhere from $150 to $400 including labor. If the refrigerant system needs to be recovered, evacuated, and recharged due to contamination or overcharge, expect costs in the range of $200 to $500 or more depending on refrigerant type and regional labor rates. Replacing a faulty high pressure switch is generally on the lower end of repair costs.

Some basic checks are within reach for a DIYer, including cleaning the outdoor coil with a garden hose, removing any physical obstructions around the outdoor unit, and confirming the outdoor fan is spinning freely. However, checking refrigerant pressures, testing the high pressure switch, and handling refrigerant require EPA certification and specialized tools. If cleaning the coil and verifying airflow do not resolve the fault, a licensed HVAC technician will need to complete the diagnosis.

Resetting the unit by cycling power may temporarily clear the code and allow the system to restart, but CH24 will return if the underlying cause has not been addressed. The code is designed to trigger after 5 switch trips within an hour, so the system will reach that threshold again quickly if the pressure problem persists. A reset is useful for confirming the fault after a repair, not as a standalone fix.