LG · A major brand in the UK. 100 codes across 6 product families, each taken from the manufacturer’s manuals. LG technical support ↗
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Type the code on your display or a word from its meaning. Each code opens its own page with what it means, whether it is safe and what you can check.
100 codes
| Code | Meaning | Stops? | Homeowner check? |
|---|---|---|---|
| bc21 | Inverter compressor IPM defect – indoor-unit (R134a stage) inverter PCB error, displayed with prefix "bc" (High Temperature split). | Yes | Yes |
| bc22 | Inverter compressor overcurrent – indoor-unit (R134a stage) inverter PCB error, displayed with prefix "bc" (High Temperature split). | Yes | Yes |
| bc23 | Inverter compressor DC link low voltage – indoor-unit (R134a stage) inverter PCB error, displayed with prefix "bc" (High Temperature split). | Yes | Yes |
| bc25 | High/low inverter input voltage – indoor-unit (R134a stage) inverter PCB error, displayed with prefix "bc" (High Temperature split). | Yes | Yes |
| bc26 | Inverter compressor activation failure – indoor-unit (R134a stage) inverter PCB error, displayed with prefix "bc" (High Temperature split). | Yes | Yes |
| bc27 | Inverter PSC/PFC fault error – indoor-unit (R134a stage) inverter PCB error, displayed with prefix "bc" (High Temperature split). | Yes | Yes |
| bc28 | Inverter DC link high voltage error – indoor-unit (R134a stage) inverter PCB error, displayed with prefix "bc" (High Temperature split). | Yes | Yes |
| bc29 | Inverter compressor overcurrent – indoor-unit (R134a stage) inverter PCB error, displayed with prefix "bc" (High Temperature split). | Yes | Yes |
| bc32 | Excessive rise of inverter compressor discharge temperature – indoor-unit (R134a stage) inverter PCB error, displayed with prefix "bc" (High Temperature split). | Yes | Yes |
| bc34 | Excessive rise of high pressure of inverter compressor – indoor-unit (R134a stage) inverter PCB error, displayed with prefix "bc" (High Temperature split). | Yes | Yes |
| bc35 | Excessive drop of low pressure of inverter compressor – indoor-unit (R134a stage) inverter PCB error, displayed with prefix "bc" (High Temperature split). | Yes | Yes |
| bc36 | Low pressure ratio error of inverter compressor – indoor-unit (R134a stage) inverter PCB error, displayed with prefix "bc" (High Temperature split). | Yes | Yes |
| bc40 | Inverter compressor CT sensor defect – indoor-unit (R134a stage) inverter PCB error, displayed with prefix "bc" (High Temperature split). | Yes | Yes |
| bc41 | Inverter compressor discharge pipe temperature sensor defect – indoor-unit (R134a stage) inverter PCB error, displayed with prefix "bc" (High Temperature split). | Yes | Yes |
| bc42 | Low pressure sensor defect of inverter compressor – indoor-unit (R134a stage) inverter PCB error, displayed with prefix "bc" (High Temperature split). | Yes | Yes |
| bc43 | High pressure sensor defect of inverter compressor – indoor-unit (R134a stage) inverter PCB error, displayed with prefix "bc" (High Temperature split). | Yes | Yes |
| bc44 | Inverter inside air temperature sensor defect – indoor-unit (R134a stage) inverter PCB error, displayed with prefix "bc" (High Temperature split). | Yes | Yes |
| bc46 | Inverter compressor suction pipe temperature sensor defect – indoor-unit (R134a stage) inverter PCB error, displayed with prefix "bc" (High Temperature split). | Yes | Yes |
| bc53 | Communication error (indoor unit → outdoor unit main PCB) – indoor-unit (R134a stage) inverter PCB error, displayed with prefix "bc" (High Temperature split). | Yes | Yes |
| bc60 | Inverter PCB EEPROM error – indoor-unit (R134a stage) inverter PCB error, displayed with prefix "bc" (High Temperature split). | Yes | Yes |
| bc62 | Excessive rise of inverter heatsink temperature – indoor-unit (R134a stage) inverter PCB error, displayed with prefix "bc" (High Temperature split). | Yes | Yes |
| bc65 | Inverter heatsink temperature sensor defect – indoor-unit (R134a stage) inverter PCB error, displayed with prefix "bc" (High Temperature split). | Yes | Yes |
| bc73 | Overcurrent (peak) detected at inverter input – indoor-unit (R134a stage) inverter PCB error, displayed with prefix "bc" (High Temperature split). | Yes | Yes |
| CH01 | Problem in remote (room) air temperature sensor – sensor on the indoor Main PCB/remote room sensor is open or short circuit. | Partly | Yes |
| CH02 | Problem in refrigerant inlet (liquid) side pipe temperature sensor of indoor unit – open or short. | Partly | Yes |
| CH03 | Bad communication between wired remote controller and indoor unit (Main PCB(Indoor) does not receive the remote controller signal). | Yes | Yes |
| CH04 | Condensate drain is blocked (THERMA V water heater). | Partly | Yes |
| CH05 | Communication error between indoor unit Main PCB and outdoor unit (Main PCB(Outdoor cycle)/inverter PCB) – indoor does not receive the outdoor signal. | Partly | Yes |
| CH06 | Problem in refrigerant outlet (gas) side pipe temperature sensor of indoor unit – open or short. | Varies by model | Yes |
| CH08 | Problem in domestic hot water (DHW) tank temperature sensor – open or short. | Partly | Yes |
| CH09 | Indoor PCB program (EEPROM) fault – optional EEPROM loosely inserted, removed, burnt, or data mismatched. | Varies by model | Yes |
| CH10 | BLDC water (circulation) pump lock – restriction or wrong connection of the BLDC water pump. | Yes | Yes |
| CH11 | Indoor unit & inverter PCB communication error (High Temperature split). | Varies by model | Yes |
| CH12 | Inverter PCB error (High Temperature split) – error occurrence in the indoor inverter PCB (see bc codes). | Varies by model | Yes |
| CH13 | Problem in solar-thermal (solar pipe) temperature sensor – open or short. | Partly | Yes |
| CH14 | Water flow problem – low flow detected during pump operation (flow sensor models) or flow switch open while the internal pump runs / closed while it is stopped (flow switch models). | Yes | Yes |
| CH15 | Water pipe overheated – leaving water temperature exceeded the protection limit. | Yes | Yes |
| CH16 | Problems in sensors – water-inlet, water-outlet and backup-heater outlet sensors (CH17/18/19) fail at the same time. | Yes | Yes |
| CH17 | Problem in water-inlet (return / PHEX inlet) temperature sensor – open or short. | Partly | Yes |
| CH18 | Problem in water-outlet (flow / PHEX outlet) temperature sensor – open or short. | Partly | Yes |
| CH19 | Problem in electric backup heater water-outlet (water-interim) temperature sensor – open or short. | Partly | Yes |
| CH20 | Electric (backup) heater overheated – thermal fuse / thermo switch cut out. | Varies by model | Yes |
| CH21 | DC peak (IPM / IGBTM fault) – compressor stopped to protect the power module after detecting its fault-out signal; inverter drive IPM or compressor defective. | Partly | Yes |
| CH22 | Max CT / CT2 current error – input over-current to the outdoor unit (inverter PCB power input exceeded). | Partly | Yes |
| CH23 | DC link voltage low or high – inverter DC-link not charging or outside limits. | Partly | Yes |
| CH24 | High pressure (switch) error – compressor stopped by the high-pressure (or low/high pressure) switch. | Partly | Yes |
| CH25 | Inverter input voltage too high or too low. | Partly | Yes |
| CH26 | DC compressor position / start-up failure (no position error, locking detection) – inverter compressor fails to start. | Partly | Yes |
| CH27 | PSC/PFC fault – AC input instant over-current / over-current in PFC module. | Partly | Yes |
| CH28 | DC link high voltage – inverter DC-link voltage too high after inverter relay on. | Partly | Yes |
| CH29 | Inverter compressor over-current (compressor phase current exceeds limit). | Partly | Yes |
| CH32 | High discharge-pipe temperature of the inverter compressor – compressor switched off. | Partly | Yes |
| CH34 | High pressure error – condensing pressure excessively high (compressor off). | Partly | Yes |
| CH35 | Low pressure error – evaporating pressure excessively low. | Partly | Yes |
| CH36 | Low pressure ratio error of inverter compressor – outdoor unit (R410A stage) error on High Temperature split; shown on outdoor 7-segment LED with unit number suffix (e.g. "36 1") and on the indoor display/remote controller. | Partly | Yes |
| CH37 | Pressure ratio too high – R410A Monobloc. | Partly | Yes |
| CH40 | Inverter compressor CT sensor error – compressor control impossible due to CT sensor fault in inverter driver. | Partly | Yes |
| CH41 | Inverter compressor discharge-pipe temperature sensor error (open/short). | Partly | Yes |
| CH42 | Low pressure sensor defect of inverter compressor – outdoor unit (R410A stage) error on High Temperature split; shown on outdoor 7-segment LED with unit number suffix (e.g. "42 1") and on the indoor display/remote controller. | Partly | Yes |
| CH43 | High pressure sensor error (open/short). | Partly | Yes |
| CH44 | Outdoor air (ambient) temperature sensor error (open/short). | Partly | Yes |
| CH45 | Condenser middle-pipe (outdoor heat-exchanger) temperature sensor error (open/short). | Partly | Yes |
| CH46 | Compressor suction-pipe temperature sensor error (open/short). | Partly | Yes |
| CH47 | Const-D-pipe sensor error (open/short) – R32 Monobloc Gen1. | Partly | Yes |
| CH48 | Condenser out-pipe temperature sensor error (open/short) – thermistor not inserted or inserted incorrectly. | Partly | Yes |
| CH49 | Defective IPM temperature sensor – outdoor unit (R410A stage) error on High Temperature split; shown on outdoor 7-segment LED with unit number suffix (e.g. "49 1") and on the indoor display/remote controller. | Partly | Yes |
| CH52 | Communication error between inverter PCB (outdoor) and Main PCB (outdoor cycle). | Yes | Yes |
| CH53 | Communication error: outdoor unit fails to receive signal from indoor unit (Main PCB(Indoor) → Main PCB(Outdoor)). | Partly | Yes |
| CH54 | Open-phase / reverse-phase (R-S-T) error – mains wiring fault on 3-phase models. | Partly | Yes |
| CH55 | Modbus communication error (Modbus ↔ indoor PCB) – R290 Monobloc. | Not stated | Yes |
| CH57 | Communication error between Main PCB (outdoor cycle) and inverter PCB (outdoor) (Hydrosplit/R290 list: "Main PCB(Indoor) → Inv PCB(Outdoor)"). | Partly | Yes |
| CH60 | Outdoor EEPROM error – EEPROM access error / checksum mismatch. | Partly | Yes |
| CH61 | High temperature in condenser pipe (condensing pressure too high). | Partly | Yes |
| CH62 | Heatsink temperature high – inverter PCB heatsink/power element overheated. | Partly | Yes |
| CH63 | Condenser-pipe temperature too low – R410A Monobloc. | Partly | Yes |
| CH65 | Heatsink temperature sensor error (open/short) – heatsink or PSCM/PFCM internal sensor cannot be read. | Partly | Yes |
| CH67 | Outdoor BLDC fan lock. | Partly | Yes |
| CH73 | Overcurrent (peak) detected at inverter input – AC input instant over-current. | Partly | Yes |
| CH86 | Outdoor unit Main PCB EEPROM error – outdoor unit (R410A stage) error on High Temperature split; shown on outdoor 7-segment LED with unit number suffix (e.g. "86 1") and on the indoor display/remote controller. | Yes | Yes |
| CH88 | PFC (inverter PCBA) EEPROM error – communication fail between PFC micom and its EEPROM. | Partly | Yes |
| CH113 | Outdoor unit liquid pipe temperature sensor error – outdoor unit (R410A stage) error on High Temperature split; shown on outdoor 7-segment LED with unit number suffix (e.g. "113 1") and on the indoor display/remote controller. | Partly | Yes |
| CH114 | Vapour-injection inlet pipe temperature sensor error (open/short). | Partly | Yes |
| CH115 | Vapour-injection outlet pipe temperature sensor error (open/short). | Partly | Yes |
| CH117 | Condenser in-pipe temperature sensor error (open/short) – thermistor not inserted or inserted incorrectly (R290). | Partly | Yes |
| CH145 | Communication error between Sub PCB (outdoor) and Main PCB (outdoor cycle) – R290. | Partly | Yes |
| CH151 | Failure of operation mode conversion at outdoor unit – outdoor unit (R410A stage) error on High Temperature split; shown on outdoor 7-segment LED with unit number suffix (e.g. "151 1") and on the indoor display/remote controller. | Yes | Yes |
| CH231 | Problem in water pressure sensor – sensor damaged or incorrectly connected. | Partly | Yes |
| CH232 | Problem in water flow sensor – flow sensor damaged or incorrectly connected. | Yes | Yes |
| CH233 | Problem in solar thermal sensor (open/short) – R290. | Partly | Yes |
| CH234 | Problem in buffer tank temperature sensor (open/short) – R290. | Partly | Yes |
| CH235 | Problem in (wall-mounted) ambient temperature sensor (open/short) – R290. | Partly | Yes |
| CH237 | Communication modem error – RS-485 modem on the indoor (IDU 485 modem) cannot communicate with Main PCB (outdoor cycle) (R290). | Yes | Yes |
| CH238 | Communication modem error – RS-485 modem on the outdoor (ODU 485 modem) cannot communicate with Main PCB (outdoor cycle) (R290). | Yes | Yes |
| DF | No or not enough water in tank (THERMA V water heater). | Yes | Yes |
| EC | ECO (energy cut-off / high-limit safety) is tripped (THERMA V water heater). | Yes | Yes |
| H1 | Water temperature is too high (THERMA V water heater). | Yes | Yes |
| H2 | Water temperature is too high (THERMA V water heater). | Yes | Yes |
| IC | ICCP (impressed-current cathodic protection anode) is not functioning (THERMA V water heater). | Yes | Yes |
| L1 | Water temperature is too low (THERMA V water heater). | Yes | Yes |
| L2 | Water temperature is too low or upper tank temperature sensor is not working (THERMA V water heater). | Yes | Yes |