What CH35 means
Low refrigerant pressure usually means the system has lost some or all of its gas charge. The low-pressure protection stops the compressor to prevent it from running dry (which causes overheating and mechanical damage).
LG AC CH35 Error — Low Pressure Fault & Fix
CH35
Quick answer
CH35 means the low-pressure sensor or switch has detected abnormally low refrigerant pressure — the system may be leaking gas.
What does the CH35 code mean?
CH35 is a low-pressure protection error. The refrigerant suction pressure has dropped below the safe operating limit.
Common causes
- Refrigerant leak (flare joints, coil corrosion, pipe damage)
- Blocked or restricted filter drier
- Electronic expansion valve stuck closed
- Pressure sensor fault (giving a false low reading)
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How to fix the CH35 error
Power off
Stop the compressor immediately.
Do not restart repeatedly
Running with low gas damages the compressor.
Call a licensed technician
They will perform a leak test, find the leak, repair it, vacuum the system, and recharge with the correct amount of refrigerant.
Check the outdoor pipes
Frost on the large (suction) pipe is a strong indicator of low gas.
Safety first: Refrigerant is a pressurised gas. Only a licensed HVAC technician with proper recovery and charging equipment should handle it.
Part you may need: Refrigerant leak repair and recharge
Common leak points in LG splits: indoor and outdoor flare nut connections, service valve caps, and evaporator U-bends.
Frequently asked questions
Can I just top up the gas?
No — without finding and fixing the leak, the gas will leak out again and CH35 will return. Always fix the leak first.
How long does a recharge last?
A properly sealed system should hold its charge for the life of the unit (10-15 years). If you need frequent recharges, there is an ongoing leak.
