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LG Single / multi-split wall units Error Codes
LG uses CH numbers across its residential splits. On North American wall units the code blinks on two LEDs instead of showing a number; LG's own blink chart is inconsistent about which LED is which digit, so confirm with a wired remote or LG's service tool when you can.
| Code | Meaning | What to check |
|---|---|---|
| CH01 | Indoor return air thermistor fault. | Measure the thermistor; check connector. How to fix → |
| CH02 | Indoor inlet pipe thermistor fault. | Measure the thermistor; check connector. How to fix → |
| CH05 | Communication failure between indoor and outdoor unit. | Outdoor breaker, interconnect wiring, connectors, boards. How to fix → |
| CH06 | Indoor outlet pipe thermistor fault. | How to fix → |
| CH09 | Indoor EEPROM error. | Indoor board. |
| CH10 | Indoor fan locked or motor failure. | Fan motor, wheel binding, connector. |
| CH12 | Indoor middle pipe thermistor fault. | How to fix → |
| CH21 | DC peak / IPM fault (compressor DC voltage too high). | Inverter board, compressor. How to fix → |
| CH22 | CT2 error: AC input current too high. | Supply voltage, compressor, overcharge. How to fix → |
| CH23 | DC link voltage too low. | Supply voltage, inverter board. How to fix → |
| CH25 | System voltage too low or too high. | Supply voltage under load. How to fix → |
| CH26 | Inverter compressor seized or not rotating. | Compressor windings and wiring. How to fix → |
| CH27 | Prospective short circuit fault (current too high). | Compressor and inverter board. How to fix → |
| CH28 | Inverter compressor DC voltage too high. | How to fix → |
| CH29 | Inverter compressor amperage too high. | Compressor, refrigerant system. How to fix → |
| CH31 | CT thermistor reading too low. | How to fix → |
| CH32 | Compressor discharge pipe temperature too high. | Low charge or restriction. How to fix → |
| CH38 | Low refrigerant (per LG support). | Leak search, flare joints; charge by weight. How to fix → |
| CH40 | CT thermistor fault. | How to fix → |
| CH41 | Compressor discharge pipe thermistor fault. | Measure the thermistor; check connector. How to fix → |
| CH44 | Outdoor inlet air thermistor fault. | How to fix → |
| CH45 | Outdoor condenser coil middle thermistor fault. | How to fix → |
| CH46 | Outdoor suction line thermistor fault. | How to fix → |
| CH48 | Outdoor coil outlet (liquid line) thermistor fault. | How to fix → |
| CH53 | Communication failure from outdoor to indoor unit. | Interconnect wiring and boards. How to fix → |
| CH60 | Outdoor PCB EEPROM checksum error. | Outdoor board. |
| CH61 | Outdoor condenser coil temperature too high. | Dirty outdoor coil, fan, recirculation, overcharge. |
| CH62 | Outdoor inverter heat sink temperature too high. | Outdoor airflow, heat sink. How to fix → |
| CH63 | Condenser coil pipe temperature too low. | |
| CH65 | Heat sink thermistor fault. | How to fix → |
| CH67 | Outdoor BLDC fan motor locked. | Fan blade obstruction, motor, connector. |
How to read the codes
- Outside North America the display shows 'CH' alternating with the number.
- On North American wall units, count the blinks on the two LEDs at the lower right of the head unit.
- LG's support pages say CH05, CH53 or E0 are communication problems, and CH38 or F4 mean low refrigerant.
Codes point to a circuit, not a part. Test before replacing boards or sensors. Inverter boards hold a dangerous charge after power-off; wait and verify DC bus voltage is gone before touching them. Refrigerant work requires EPA 608 certification.
Source: LG Canada: Single / Multi-Split Air Conditioner Error Codes; LG US: Air Conditioner Guide to Error Codes. The "meaning" column follows the manufacturer's wording; "what to check" is our field summary. Always go by the label on the furnace you're working on.
Related
- Mini-split communication error troubleshooting
- Mini-split flare connections (the usual leak point)
- Look up any mini-split code
Other brands
- Daikin FTX / FVXS / FDMQ with RXL outdoor (19 Series)
- Fujitsu Halcyon / Airstage splits (indicator lamp codes)
- MRCOOL DIY E Star 4th Generation
- Mitsubishi Electric MSZ-GL / MSY-GL (failure mode recall)
- Senville AURA / LETO
- Gree Livo / All-Match with LIV outdoor (R-32)
- Pioneer Diamante / Quantum (WYT-17, WYT-20, WYT-24, WYT-25, WYT-FA)
- Lennox Mini-splits: MLB / MPC / 3PC outdoor with M22A, M33C, MWMC, MCFA/B, MFMA indoor
- ACiQ Single-zone wall mount, R-454B (ACiQ-xxWS / -xxW-BL with -xxZS / -xxZPL outdoor)
- Midea High wall ductless DLFSHB (DLFSHBH09XAK, -12XAJ, -12XAK, -18XAK, -24XAK)
- Klimaire KSIE inverter wall mount (2014–2016 models, e.g. KSIE012-H120-SW)
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