LG fault codes
48 documented codes for LG mini-splits, each cited to the manufacturer's own manual. LG uses one CH## error-code set across its residential ductless line: single-zone wall-mount (LS/LA/LAN indoor + LSU/LAU outdoor), Art Cool, ceiling cassette, ducted/LGRED, and the Multi F / Multi F MAX multi-zone systems (LMU outdoor units). CH01-CH12 are indoor-unit faults and CH21-CH73 are outdoor-unit faults, except CH05/CH53 which are the two ends of the same indoor-to-outdoor communication fault. LG's commercial Multi V VRF equipment uses the same low numbers plus a much larger extended code set that is NOT covered here..
Mini-Split codes
| Code | Meaning | Severity |
|---|---|---|
| CH00 | No error | Status |
| CH01Indoor unit LED1 (units place) blinks 1 time | Indoor unit room | Soft lockout |
| CH02Indoor unit LED1 (units place) blinks 2 times | Indoor unit inlet pipe sensor error | Soft lockout |
| CH03Indoor unit LED1 (units place) blinks 3 times | Wired remote controller | Soft lockout |
| CH04Indoor unit LED1 (units place) blinks 4 times | Drain pump / float switch error | Soft lockout |
| CH05Indoor unit LED1 (units place) blinks 5 times | Communication error between the indoor unit and the outdoor unit | Soft lockout |
| CH06Indoor unit LED1 (units place) blinks 6 times | Indoor unit outlet pipe sensor error | Soft lockout |
| CH07Indoor unit LED1 (units place) blinks 7 times | Different mode operation error | Warning |
| CH09Indoor unit LED1 (units place) blinks 9 times | Indoor unit EEPROM error | Hard lockout |
| CH10Indoor unit LED2 (tens place) blinks 1 time, LED1 does not blink | Indoor unit BLDC fan motor lock | Soft lockout |
| CH12Indoor unit LED1 (units place) blinks 2 times and LED2 (tens place) blinks 1 time | Indoor unit middle pipe sensor error | Soft lockout |
| CH21Outdoor LED01 (red) blinks 2 times, LED02 (green) blinks 1 time | DC Peak / IPM fault | Hard lockout |
| CH22Outdoor LED01 (red) blinks 2 times, LED02 (green) blinks 2 times | CT2 | Soft lockout |
| CH23Outdoor LED01 (red) blinks 2 times, LED02 (green) blinks 3 times | DC link voltage error - the DC bus inside the inverter has dropped below about 140 VDC or risen above about 420 VDC | Soft lockout |
| CH24Outdoor LED1 blinks 2 times, LED2 blinks 4 times | Pressure switch / heat sink protection has tripped | Hard lockout |
| CH25Outdoor LED01 (red) blinks 2 times, LED02 (green) blinks 5 times | AC low / high voltage | Soft lockout |
| CH26Outdoor LED01 (red) blinks 2 times, LED02 (green) blinks 6 times | DC compressor position error | Hard lockout |
| CH27Outdoor LED01 (red) blinks 2 times, LED02 (green) blinks 7 times | PSC / PFC fault - overcurrent in the power factor correction stage between the AC input and the DC converter circuit of the inverter board | Hard lockout |
| CH28Outdoor LED1 blinks 2 times, LED2 blinks 8 times | Inverter compressor DC voltage is too high | Soft lockout |
| CH29Outdoor LED01 (red) blinks 2 times, LED02 (green) blinks 9 times | Compressor phase overcurrent - the current into the compressor windings is higher than allowed | Hard lockout |
| CH31Outdoor LED1 blinks 3 times, LED2 blinks 1 time | Current transformer | Soft lockout |
| CH32Outdoor LED01 (red) blinks 3 times, LED02 (green) blinks 2 times | Inverter compressor discharge pipe | Soft lockout |
| CH34Outdoor LED1 blinks 3 times, LED2 blinks 4 times (2-LED type; the service manual pairs CH34 with CH35 in one row) | High pressure sensor error | Soft lockout |
| CH35Outdoor LED01 (red) blinks 3 times, LED02 (green) blinks 5 times | Low pressure error - suction pressure has dropped below the recommended limit | Soft lockout |
| CH36Outdoor LED1 blinks 3 times, LED2 blinks 6 times (2-LED type; service manual lists this row as '36 (38)') | Refrigerant leakage detection | Hard lockout |
| CH37Outdoor LED1 blinks 3 times, LED2 blinks 7 times (2-LED type) | Compression ratio limit exceeded | Soft lockout |
| CH38Outdoor LED1 blinks 3 times, LED2 blinks 6 times (2-LED type; service manual lists this row as '36 (38)') | Refrigerant leakage detection - the system is low on refrigerant | Hard lockout |
| CH39Outdoor LED01 (red) blinks 3 times, LED02 (green) blinks 9 times | Communication error between the PFC MICOM and the inverter MICOM - the two microcontrollers on the outdoor unit's power board have lost contact with each other | Soft lockout |
| CH40Outdoor LED01 (red) blinks 4 times, LED02 (green) does not blink | Current transformer | Hard lockout |
| CH41Outdoor LED01 (red) blinks 4 times, LED02 (green) blinks 1 time | Inverter compressor discharge pipe | Soft lockout |
| CH42Outdoor LED1 blinks 4 times, LED2 blinks 2 times (2-LED type) | Low pressure sensor open or short | Soft lockout |
| CH43Outdoor LED01 (red) blinks 4 times, LED02 (green) blinks 3 times | High pressure sensor is disconnected or shorted out | Soft lockout |
| CH44Outdoor LED01 (red) blinks 4 times, LED02 (green) blinks 4 times | Outdoor air | Soft lockout |
| CH45Outdoor LED01 (red) blinks 4 times, LED02 (green) blinks 5 times | Mid-pipe thermistor of the outdoor unit condenser coil is disconnected or shorted out | Soft lockout |
| CH46Outdoor LED01 (red) blinks 4 times, LED02 (green) blinks 6 times | Outdoor unit suction pipe thermistor is disconnected or shorted out | Soft lockout |
| CH48Outdoor LED01 (red) blinks 4 times, LED02 (green) blinks 8 times | Outdoor unit condenser coil outlet | Soft lockout |
| CH51Outdoor LED01 (red) blinks 5 times, LED02 (green) blinks 1 time | Over capacity / combination ratio out of range | Hard lockout |
| CH53Outdoor LED01 (red) blinks 5 times, LED02 (green) blinks 3 times | Communication failure from the outdoor unit to the indoor unit | Soft lockout |
| CH54Outdoor LED01 (red) blinks 5 times, LED02 (green) blinks 4 times | Open phase / reverse phase error - the outdoor unit's incoming power is missing a leg or wired in the wrong order | Hard lockout |
| CH60Outdoor LED01 (red) blinks 6 times, LED02 (green) does not blink | Outdoor unit PCB EEPROM check sum error | Hard lockout |
| CH61Outdoor LED01 (red) blinks 6 times, LED02 (green) blinks 1 time | Outdoor unit condenser coil pipe temperature is too high | Soft lockout |
| CH62Outdoor LED01 (red) blinks 6 times, LED02 (green) blinks 2 times | Outdoor unit inverter compressor PCB heat sink temperature is too high | Soft lockout |
| CH63Outdoor LED1 blinks 6 times, LED2 blinks 3 times | Condenser coil pipe thermistor temperature is too low | Soft lockout |
| CH65Outdoor LED01 (red) blinks 6 times, LED02 (green) blinks 5 times | Heat sink thermistor is disconnected or shorted out | Soft lockout |
| CH67Outdoor LED01 (red) blinks 6 times, LED02 (green) blinks 7 times | Outdoor BLDC fan motor lock error | Hard lockout |
| CH72Outdoor LED1 blinks 7 times, LED2 blinks 2 times (2-LED type) | Four-way | Soft lockout |
| CH73Outdoor LED01 (red) blinks 7 times, LED02 (green) blinks 3 times | PSC / PFC overcurrent error detected in software - the outdoor unit's power factor correction stage saw a current peak beyond its limit | Soft lockout |
| CH93 | Indoor / outdoor unit communication error | Soft lockout |
Looking it up by flash count?
If you counted LED flashes rather than reading a code number, start here:
Manuals used for this page
- MULTI F / MULTI F MAX Outdoor Unit Installation Manual (LG Electronics U.S.A., Inc.) · checked 2026-08-25
- Single Zone Four-Way Ceiling-Cassette Installation Manual (LG Electronics U.S.A., Inc.) · checked 2026-08-25
- Convertible Mid-Static Ducted LGRED Degree System Installation Manual (LG Electronics U.S.A., Inc.) · checked 2026-08-25
- Defining Common Error Codes - Standard Wall-Mounted High-Efficiency Single Zone Systems (LG Electronics U.S.A. - Commercial Air Conditioning) · checked 2026-08-25
- Room Air Conditioner SVC Manual (General) - Trouble Shooting Guide with Error Code (LG Electronics) · checked 2026-08-25
- LG Air Conditioner - Guide to Error Codes (LG USA Support help library) (LG Electronics U.S.A., Inc.) · checked 2026-08-25