LG Heat Pump Error Codes — Meanings, Causes & Repair in Greater Vancouver

Seeing a fault code on your LG heat pump? This guide explains what the most common LG heat pump error codes mean, what’s safe to check yourself, and when to call HeatLand’s licensed HVAC technicians for LG heat pump repair across Metro Vancouver and the Fraser Valley.

The codes below apply across common LG models (Art Cool, Multi F, LGRED). Meanings follow LG’s documented fault codes — always confirm against your unit’s own manual, because exact wording can vary by model, control board and firmware.

How to read LG heat pump error codes

LG displays a self-diagnosis fault as 'CH' followed by a two-digit number (e.g. CH 05, CH 38) on the wired/wireless remote and the indoor unit's fascia display. On units without a display the same number is shown by blinking front-panel LEDs, and the outdoor PCB indicates it via red/green LED flash counts. The lowest-numbered code is shown first if several occur at once. The same fault number is shared across LG ductless lines including Art Cool, Multi F multi-zone, and LGRED low-temperature heating models.

LG heat pump error codes & what they mean

These are the LG heat pump codes our Greater Vancouver technicians see most. Anything marked pro repair involves electrical, refrigerant, sensor or control-board work that must be done by a licensed HVAC technician — never open the indoor/outdoor unit or refrigerant lines yourself.

Code	What it usually means	Common causes	Safe to check yourself
CH 01	Indoor unit return-air (room) temperature sensor fault — open or short circuit on the indoor air thermistor pro repair	Failed indoor air thermistor; Loose or disconnected sensor plug on the indoor PCB; Damaged sensor wiring	Turn the unit off at the breaker for a few minutes, then restore power and restart once to clear a one-time glitch
CH 02	Indoor coil inlet pipe temperature sensor fault — open or short circuit on the inlet pipe thermistor pro repair	Failed inlet pipe thermistor; Loose sensor connection on the indoor PCB; Damaged sensor wiring	Power the unit off at the breaker briefly, then restore power and restart once
CH 03	Communication error between the indoor unit and the wired remote controller (wiring or controller setting error) pro repair	Incorrect or loose remote-controller cable wiring; Remote controller set to wrong single/group mode for the installation; Damaged controller cable	Turn the unit off at the breaker for about 2 minutes, then restore power; Confirm the wired thermostat/remote is seated and undamaged
CH 04	Drain pump / float switch fault — the condensate float switch has tripped (high water level), indicating water is not draining from the indoor unit pro repair	Blocked or kinked condensate drain line; Failed or clogged condensate pump; Stuck or failed float switch	Clear any visible obstruction or kink in the external condensate drain hose where accessible; Restore power and restart once after the water level drops
CH 05	Communication error between the indoor and outdoor units — the serial signal between the units has been lost (often appears a few minutes after power-up) pro repair	Incorrect, loose, or damaged interconnecting wiring between indoor and outdoor units; Tripped breaker or power loss to one unit; Defective indoor or outdoor PCB	Confirm both the indoor and outdoor units have power and the breaker is not tripped; Turn off power at the breaker for about 5 minutes, then restore it and restart
CH 06	Indoor coil outlet pipe temperature sensor fault — open or short circuit on the outlet pipe thermistor pro repair	Failed outlet pipe thermistor; Loose sensor connection on the indoor PCB; Damaged sensor wiring	Power the unit off at the breaker briefly, then restore power and restart once
CH 07	Operating-mode conflict on a multi-split system — indoor units sharing one outdoor unit are set to conflicting modes (e.g. one heating while another cools). All zones must run in compatible modes DIY-checkable	Indoor units in different rooms set to opposing modes (heat vs cool/dehumidify); Mode changed on one zone while another zone is running an incompatible mode	Set every indoor unit on the system to the same mode family (all heating, or all cooling/dehumidifying); Turn the conflicting unit off at the remote, then back on, and select a matching mode
CH 09	Indoor PCB EEPROM checksum error — defective PCB or bad EEPROM connection pro repair	Loose connection or dry solder joint at the EEPROM on the indoor PCB; Corrupted EEPROM data; Defective indoor control board	Turn power off at the breaker for a few minutes, then restore and restart once
CH 10	Indoor BLDC fan motor lock — the indoor fan motor is not turning at the expected speed (motor or PCB fault) pro repair	Indoor fan blocked by debris; Failed indoor BLDC fan motor; Loose fan motor connector	Turn the unit off and remove any visible debris obstructing the indoor blower or vents where reachable; Clean the indoor air filters; Restore power and restart once
CH 21	IPM fault / inverter compressor over-current — over-current detected in the inverter's DC power circuit pro repair	Faulty inverter PCB / IPM module; Short-circuited or grounded compressor; Compressor overload	Turn power off at the breaker for about 5 minutes, then restore and restart once
CH 22	Maximum current (CT2) fault — the measured operating current has exceeded the allowed maximum (compressor over-current) pro repair	Compressor over-current / overload; Refrigerant overcharge or system restriction; Faulty inverter PCB	Power off at the breaker for about 5 minutes, then restore and restart once
CH 23	DC link low voltage — the DC link voltage to the inverter has dropped below its threshold pro repair	Faulty inverter charging resistor on the outdoor PCB; Low incoming supply voltage; Defective outdoor PCB	Confirm the breaker is on and not tripped; Power off at the breaker for a few minutes, then restore and restart once
CH 24	Low / high pressure switch open — a refrigerant low-pressure or high-pressure switch has tripped, stopping the compressor pro repair	Low refrigerant charge or refrigerant leak (low-pressure trip); Blocked outdoor coil or restricted airflow (high-pressure trip); Failed pressure switch	Make sure the outdoor unit's coil and surroundings are clear of leaves, snow, or debris and have free airflow; Clean the indoor filters; Power off at the breaker for about 2 minutes, then restore and restart once
CH 25	Abnormal AC supply voltage — incoming mains voltage is too low or too high (out of acceptable range) pro repair	Incoming supply voltage below ~140 V or above the high-voltage limit; Utility supply problem or undersized wiring; Defective outdoor PCB	Confirm the breaker is on and other appliances on the circuit work normally; Power off at the breaker briefly, then restore and restart once
CH 26	DC compressor position error — the inverter cannot detect correct rotor position, often indicating a seized or stalled compressor pro repair	Seized or stalled inverter compressor; Incorrect or loose compressor wiring; Faulty inverter PCB	Power off at the breaker for about 5 minutes, then restore and restart once
CH 27	PSC / reactor (PFC) fault — a problem with the inverter module or the reactor circuit pro repair	Disconnected or faulty reactor; Defective inverter / PFC module on the outdoor PCB	Power off at the breaker for a few minutes, then restore and restart once
CH 28	DC link high voltage — the DC voltage supplied to the inverter is too high pro repair	Excessive incoming supply voltage; Defective inverter / outdoor PCB	Power off at the breaker briefly, then restore and restart once
CH 29	Inverter compressor over-current — compressor input current is excessive pro repair	Overload (pipe restriction, restricted airflow, EEV defect, or refrigerant overcharge); Compressor insulation or motor damage; Low input voltage	Make sure the outdoor unit has clear airflow and is free of debris or snow; Clean the indoor filters; Power off at the breaker for about 5 minutes, then restore and restart once
CH 32	Inverter compressor discharge pipe temperature too high (above ~105 C), usually indicating low refrigerant charge or a system blockage pro repair	Refrigerant shortage / leak; Restriction or blockage in the refrigerant circuit; Poor outdoor airflow	Ensure the outdoor coil and surroundings are clear and well ventilated; Clean the indoor filters; Power off at the breaker for about 2 minutes, then restore and restart once
CH 33	Fixed-speed (constant) compressor discharge pipe temperature too high (above ~105 C), usually indicating low refrigerant charge or a system blockage pro repair	Refrigerant shortage / leak; Restriction or blockage in the refrigerant circuit; Poor outdoor airflow	Ensure the outdoor coil and surroundings are clear and well ventilated; Clean the indoor filters; Power off at the breaker for about 2 minutes, then restore and restart once
CH 38	Low refrigerant (gas) detected — the system has lost refrigerant charge. May also be triggered by an electrical/power fault. The unit limits operation to protect itself pro repair	Refrigerant leak / undercharge; Improper installation or evacuation; Unstable power or electrical fault	Turn off power at the breaker (or unplug) for about 5 minutes, then restore power to clear a temporary power-related trip; If it returns after one reset, stop using and call a technician
CH 39	Communication error between the PFC and inverter PCBs inside the outdoor unit pro repair	PCB defect or wiring fault between boards; Mismatched control software versions; Damaged outdoor inverter PCB	Power off at the breaker for a few minutes, then restore and restart once
CH 40	Current transformer (CT) circuit malfunction — the current-sensing circuit on the outdoor inverter board has failed pro repair	Faulty CT sensor circuit; Defective outdoor inverter PCB	Power off at the breaker briefly, then restore and restart once
CH 41	Inverter compressor discharge pipe temperature sensor fault — open or short circuit on the inverter discharge thermistor pro repair	Failed discharge pipe thermistor; Loose sensor connection on the outdoor PCB; Damaged sensor wiring	Power off at the breaker briefly, then restore and restart once
CH 44	Outdoor air temperature sensor fault — open or short circuit on the outdoor air thermistor pro repair	Failed outdoor air thermistor; Loose sensor connection on the outdoor PCB; Damaged sensor wiring	Power off at the breaker briefly, then restore and restart once
CH 45	Outdoor condenser coil (pipe) temperature sensor fault — open or short circuit on the condenser coil thermistor pro repair	Failed condenser coil thermistor; Loose sensor connection on the outdoor PCB; Damaged sensor wiring	Power off at the breaker briefly, then restore and restart once
CH 46	Compressor suction pipe temperature sensor fault — open or short circuit on the suction thermistor pro repair	Failed suction pipe thermistor; Loose sensor connection on the outdoor PCB; Damaged sensor wiring	Power off at the breaker briefly, then restore and restart once
CH 51	Over capacity — the connected indoor capacity exceeds what the outdoor unit supports (over-load combination) pro repair	Too many or too large indoor units connected for the outdoor unit; Incorrect capacity/address setting during installation	Power off at the breaker briefly, then restore and restart once
CH 52	Communication error between the main micom and sub micom on the outdoor control board pro repair	Poor or lost communication between control microprocessors; Defective outdoor PCB	Power off at the breaker for a few minutes, then restore and restart once
CH 53	Communication error between the indoor and outdoor units (indoor-to-outdoor signal lost). Often temporary from power instability pro repair	Incorrect, loose, or damaged interconnecting wiring; Power instability or breaker trip on one unit; Defective indoor or outdoor PCB	Confirm both units have power and the breaker is not tripped; Power off at the breaker for about 5 minutes, then restore and restart
CH 54	Outdoor 3-phase power supply reverse-phase / missing-phase error — incorrect phase wiring detected (common after a power outage or electrical work on 3-phase units) pro repair	Reversed or missing phase in the supply wiring; Power-company phase change or outage; Loose supply connection	Reset the circuit breaker once (off, then on); Confirm power has fully returned after any outage
CH 61	Condenser coil temperature too high — overheating (typically the outdoor unit in cooling, or the indoor coil in heating) pro repair	Blocked outdoor coil or restricted airflow; Dirty air filter; Obstructions around the outdoor unit	Clear leaves, snow, and any obstacles from around the outdoor unit so air flows freely; Clean the indoor air filters; Power off at the breaker for a few minutes, then restore and restart once
CH 62	Heat-sink (IPM) temperature too high on the outdoor inverter board pro repair	Poor outdoor airflow / clogged condenser; Failed outdoor fan; Defective inverter heat-sink or PCB	Make sure the outdoor unit has clear airflow and is free of debris or snow; Power off at the breaker for a few minutes, then restore and restart once
CH 63	Condenser coil temperature too low pro repair	Low refrigerant charge; Low outdoor ambient operating conditions; Failed coil sensor	Ensure the outdoor unit is clear of snow and debris; Power off at the breaker briefly, then restore and restart once
CH 65	Heat-sink temperature sensor fault — open or short circuit on the inverter heat-sink thermistor pro repair	Failed heat-sink thermistor; Loose sensor connection; Defective outdoor inverter PCB	Power off at the breaker briefly, then restore and restart once
CH 67	Outdoor BLDC fan motor lock — the outdoor fan is not turning at the expected speed (motor or circuit fault) pro repair	Outdoor fan blocked by debris, ice, or snow; Failed outdoor BLDC fan motor; Loose fan connector	With power off, remove snow, ice, or debris obstructing the outdoor fan where safely reachable; Restore power and restart once
CH 73	PFC (power factor correction) software fault — inverter PCB input current exceeded its peak limit pro repair	Power supply surge or instability; Defective PFC circuit / inverter PCB; Compressor overload	Power off at the breaker for a few minutes, then restore and restart once
CH 93	Communication problem between the indoor and outdoor units during the test run or initial operation pro repair	Loose or incorrect power/communication connections; Installation wiring not completed; Defective PCB	Confirm both units have power; Power off at the breaker briefly, then restore and restart once
CH 105	Communication error between the main control board and the outdoor fan-control board pro repair	Poor or lost communication between the boards; Wiring fault between control and fan boards; Defective outdoor PCB or fan-driver board	Power off at the breaker for a few minutes, then restore and restart once
CH 237	Power-supply configuration error on newer (post-2021) models that require separate dedicated power for the indoor and outdoor units pro repair	Indoor and outdoor units not supplied from correct separate power sources; Power plug not connected directly to a wall outlet (extension cord / power strip used)	Plug the unit's power cord directly into a proper wall outlet, not a power strip or extension cord; Power off at the breaker briefly, then restore and restart once

LG heat pump codes we get called for most

CH 01 — Indoor unit return-air (room) temperature sensor fault — open or short circuit on the indoor air thermistor

Typical causes include failed indoor air thermistor; loose or disconnected sensor plug on the indoor pcb; damaged sensor wiring. A few things are safe to check yourself (Turn the unit off at the breaker for a few minutes, then restore power and restart once to clear a one-time glitch), but the repair is a licensed HVAC technician job. HeatLand diagnoses and fixes CH 01 on LG heat pumps throughout Greater Vancouver.

CH 21 — IPM fault / inverter compressor over-current — over-current detected in the inverter's DC power circuit

Typical causes include faulty inverter pcb / ipm module; short-circuited or grounded compressor; compressor overload. A few things are safe to check yourself (Turn power off at the breaker for about 5 minutes, then restore and restart once), but the repair is a licensed HVAC technician job. HeatLand diagnoses and fixes CH 21 on LG heat pumps throughout Greater Vancouver.

CH 24 — Low / high pressure switch open — a refrigerant low-pressure or high-pressure switch has tripped, stopping the compressor

Typical causes include low refrigerant charge or refrigerant leak (low-pressure trip); blocked outdoor coil or restricted airflow (high-pressure trip); failed pressure switch. A few things are safe to check yourself (Make sure the outdoor unit's coil and surroundings are clear of leaves, snow, or debris and have free airflow; Clean the indoor filters), but the repair is a licensed HVAC technician job. HeatLand diagnoses and fixes CH 24 on LG heat pumps throughout Greater Vancouver.

CH 10 — Indoor BLDC fan motor lock — the indoor fan motor is not turning at the expected speed (motor or PCB fault)

Typical causes include indoor fan blocked by debris; failed indoor bldc fan motor; loose fan motor connector. A few things are safe to check yourself (Turn the unit off and remove any visible debris obstructing the indoor blower or vents where reachable; Clean the indoor air filters), but the repair is a licensed HVAC technician job. HeatLand diagnoses and fixes CH 10 on LG heat pumps throughout Greater Vancouver.

Is it safe to keep running a LG heat pump with a fault code?

Most LG fault codes put the heat pump into a safe lockout for a reason. You can safely check the basics — the power and breaker on, the indoor filter clean, the outdoor unit clear of snow, ice and debris, and the remote set to the correct mode and temperature — and restart it once. If the code returns, stop and book a technician. Mini-split and heat-pump faults are electrical and refrigerant issues — never open the indoor or outdoor unit, and never touch the wiring or refrigerant lines yourself.

LG heat pump repair across Greater Vancouver

HeatLand has kept Metro Vancouver homes comfortable since 1999. Our licensed, insured technicians diagnose and repair LG heat pumps — sensor and thermistor errors, indoor-to-outdoor communication faults, fan and compressor problems, refrigerant and pressure faults, and control-board issues — including units we didn’t install. We’re brand-agnostic, carry common parts, and give you an honest repair-or-replace assessment with upfront pricing and a free estimate. If your heat pump is beyond economical repair, we’ll show you right-sized, high-efficiency replacement options and the rebates available.

Need it sorted fast? We offer priority emergency heat pump repair. Explore Heat Pump services, browse all heat pump error codes by brand, or request a free estimate.

LG heat pump service areas

We repair LG heat pumps across Greater Vancouver and the Fraser Valley, including:

LG heat pump error code FAQs

Can I reset my LG heat pump myself?

Yes — power-cycling the unit at the breaker once is generally safe after you’ve checked the basics (the power and breaker on, the indoor filter clean, the outdoor unit clear of snow, ice and debris, and the remote set to the correct mode and temperature). If the heat pump faults again right away, stop and note the code — repeatedly resetting a heat pump that keeps locking out can mask a real problem. Call a licensed HVAC technician to diagnose it.

What does the LG CH 01 code mean?

On LG heat pumps, CH 01 commonly indicates indoor unit return-air (room) temperature sensor fault — open or short circuit on the indoor air thermistor. Confirm the exact meaning against your unit’s manual — codes can vary by model and series — and have the repair done by a licensed HVAC technician. HeatLand fixes this across Greater Vancouver.

Do you repair LG heat pumps you didn’t install?

Yes. HeatLand is brand-agnostic and services LG heat pumps throughout Metro Vancouver and the Fraser Valley, whether or not we installed the unit. We carry common parts and give you an honest repair-or-replace assessment.

Is a LG heat pump fault code an emergency?

No heat in cold weather or no cooling in a heat wave is worth treating urgently. For priority heat pump repair across Greater Vancouver, call (604) 330-3812.

How much does LG heat pump repair cost in Vancouver?

It depends on the fault. Many LG codes point to sensors, thermistors, capacitors or control parts — usually far cheaper than replacement. We give upfront pricing and a free estimate before any work.

More Heat Pump error-code guides

HeatLand repairs every major heat pump brand across Greater Vancouver. More brand guides: