LG Air Conditioner Error Code CH24
A safety switch has cut the system because refrigerant pressure went outside its safe range. Blocked airflow at the outdoor unit is the user-fixable cause; everything on the pressure side itself needs a licensed technician.
Also shown as: 24
Applies to: Residential split and multi-split systems fitted with pressure switches
Common causes
- Outdoor airflow blocked, pushing pressure too high
- Outdoor fan not running
- Refrigerant charge wrong (too much or too little)
- Pressure switch or its wiring faulty
What to check, in order
- Check the outdoor unit and clear away anything blocking the fan or coil: leaves, covers, boxes, or a fence panel fitted too close.
- Clean the indoor air filters, let them dry completely, and refit them.
- Restart once after clearing the airflow. If the code trips again, leave the unit off: pressure testing is licensed work.
Clear the code and test
- Fix what the checks above found first — a filter cleaned, an obstruction removed, the breaker restored. Clearing the code without fixing the cause only brings it back.
- Restore power at the breaker and switch the unit on with the remote.
- Run the unit in cooling or heating for ten to fifteen minutes and watch whether the code returns; some codes only appear after the compressor has run for a while.
- If the unit runs with no code, the fault is cleared. If the code returns, write down the code and whether the indoor or outdoor unit shows it before calling a technician — it speeds up the diagnosis.
When to call a professional
Most cases are solved by the checks above. Book a technician if any of these apply:
- The code comes back after you have run the checks and a test cycle.
- You smell burning, see sparks or scorch marks, or the breaker trips.
- Water is leaking and you cannot stop it.
- The fix needs panels opened beyond what your manual describes, or a part tested with a meter, and you are not set up for that.
When you call, give the brand, the code CH24, your model number (on a label on the side of the indoor unit) and the checks you already ran. It shortens the visit.
Parts that may be involved
Pressure switchOutdoor fan motor
Parts are model-specific. Find your model number first — usually on a label on the side of the indoor unit — and match the part to that number before ordering.
Questions people ask about CH24
What does CH24 mean on a LG air conditioner?
CH24 means: Pressure switch tripped (high or low pressure). A safety switch has cut the system because refrigerant pressure went outside its safe range. Blocked airflow at the outdoor unit is the user-fixable cause; everything on the pressure side itself needs a licensed technician.
Can I fix LG CH24 myself?
Start yourself: the checks on this page cover the causes you can reach without opening the machine up. If they point to a faulty part, testing or replacing it is usually a technician job.
How do I clear LG CH24?
Fix what the checks above found first — a filter cleaned, an obstruction removed, the breaker restored. Clearing the code without fixing the cause only brings it back. Restore power at the breaker and switch the unit on with the remote. Run the unit in cooling or heating for ten to fifteen minutes and watch whether the code returns; some codes only appear after the compressor has run for a while.
Sources checked
The meaning and checks for this code were checked against the sources above in November 2026. Codes vary by model and region; if your manual lists a different meaning for your exact model, follow the manual.