LG Mini-Split Code CH37
Soft lockoutShown as: Outdoor LED1 blinks 3 times, LED2 blinks 7 times (2-LED type)
Compression ratio limit exceeded. The ratio between discharge and suction pressure is outside the compressor's safe envelope, so the unit stops. Points at a restriction, a closed service valve, or a charge problem.
Manual wording: “Failure compressing ratio”
Documented for: LG single-zone room air conditioner / mini-split outdoor units
Likely causes, most common first
- Overload operation - outdoor fan restricted, screened, or blocked
- Service (SVC) valve locked or left closed
- Bad compressor sensor
- EEV connector displaced or poor EEV assembly
- EEV body clogging
- Refrigerant leakage (insufficient charge)
- Refrigerant overcharge
What you can safely check yourself
- Clear leaves, grass clippings, snow, or debris away from the outdoor coil and fan
- Check and clean the indoor air filters
When to call a technician
A closed service valve, a clogged expansion valve, or an incorrect charge all need a licensed technician with gauges. Never operate the service valves yourself.
A LG mini-split throwing this code repeatedly has a reason — clearing the code without fixing the cause just hides it.
Source
- Room Air Conditioner SVC Manual (General) - Trouble Shooting Guide with Error Code (LG Electronics, All LG single-zone room air conditioner / mini-split chassis (SW, SB, SC, S4, S5, SH, SA, SJ, SK)) · checked 2026-08-25