LG Mini-Split Code CH31
Soft lockoutShown as: Outdoor LED1 blinks 3 times, LED2 blinks 1 time
Current transformer (CT) reading is too low - the outdoor board is not sensing the current it expects for the compressor speed it commanded.
Manual wording: “Current to the current transformer (CT) thermistor is too low.”
Documented for: LS091HSV / LS121HSV systems (LSN091HSV / LSN121HSV indoor, LSU091HSV / LSU121HSV outdoor)
Likely causes, most common first
- Current to the current transformer (CT) thermistor is too low
What you can safely check yourself
- Turn the system off at the breaker for three minutes and back on
When to call a technician
The current transformer sits on the outdoor inverter board. Diagnosis is technician work.
A LG mini-split throwing this code repeatedly has a reason — clearing the code without fixing the cause just hides it.
Source
- Defining Common Error Codes - Standard Wall-Mounted High-Efficiency Single Zone Systems (LG Electronics U.S.A. - Commercial Air Conditioning, LS091HSV and LS121HSV systems (LSN091HSV / LSN121HSV indoor units, LSU091HSV / LSU121HSV outdoor units)) · checked 2026-08-25