If your LG mini split has stopped and the display shows “CH” followed by a number, that number already tells you where the problem is. LG mini split error codes up to CH10 point to the indoor unit, codes from CH21 upward come from the outdoor unit, and CH05 or CH53 mean the two units have stopped talking to each other.
Every code below was checked against LG’s own documents: the error code guides in LG’s help library and LG’s fault code sheet for split systems. Start with one simple reset, then use the full list to see whether it’s something you can check yourself or a job for a technician.
Table of Contents
First step for any LG mini split error code: a 5-minute reset
LG gives the same first step for almost every code, because many of them are caused by a brief power problem rather than a broken part:
- Turn the unit off with the remote.
- Unplug it or switch off its circuit breaker.
- Wait about five minutes.
- Restore power, turn the unit back on and see whether the code comes back.
If the code doesn’t return, it was most likely a temporary electrical issue and you can keep using the unit. If it comes straight back, or the breaker trips again, stop there. LG’s advice is not to keep resetting a breaker that won’t stay on, and not to open the unit or replace parts yourself.
Where LG mini split error codes appear
On units with a display, the code appears on the indoor unit as CH plus a number, for example CH05 or CH38. A wired wall controller shows the same code. Units without a display signal an error by blinking a lamp on the indoor unit; LG’s owner’s manuals describe the lamp blinking at two-second intervals, and the number of blinks gives the code. Which lamp counts the tens and which counts the units depends on the model, so check the manual for yours.
How to read LG mini split error codes by number
| Codes | Where the problem is | Can you check it yourself? |
|---|---|---|
| CH01–CH10 | Indoor unit: sensors, drain, fan, control board | Partly: filters, airflow and the drain |
| CH05, CH53 | Communication between indoor and outdoor units | Partly: power to the outdoor unit |
| CH07, CH51 | Multi-zone setup | CH07 yes: set all rooms to the same mode |
| CH21–CH29 | Outdoor unit: compressor drive and power supply | Only the reset |
| CH24, CH32–CH38 | Refrigerant pressure and temperature | No, technician |
| CH41–CH46, CH65 | Outdoor unit sensors | No, technician |
| CH60–CH67 | Outdoor board, overheating, outdoor fan | Partly: clear the outdoor unit |
Full list of LG mini split error codes
| Code | Unit | What it means | Common causes |
|---|---|---|---|
| CH01 | Indoor | Indoor air temperature sensor open or shorted | Faulty sensor, loose connector, indoor board |
| CH02 | Indoor | Indoor coil inlet pipe sensor open or shorted | Faulty sensor, loose connector |
| CH03 | Indoor | No communication with the wired wall controller | Controller wiring or settings |
| CH04 | Indoor | Drain pump or float switch: water level too high | Blocked drain, failed pump, stuck float |
| CH05 | Indoor | Indoor unit not receiving signal from the outdoor unit | No power to outdoor unit, loose or wrong wiring, board |
| CH06 | Indoor | Indoor coil outlet pipe sensor open or shorted | Faulty sensor, loose connector |
| CH07 | Indoor | Rooms set to different modes (multi-zone) | One room heating while another cools |
| CH09 | Indoor | Indoor board memory error (EEPROM) | Indoor control board |
| CH10 | Indoor | Indoor fan motor locked | Blocked fan, motor, indoor board |
| CH21 | Outdoor | Inverter fault (DC peak, compressor current spike) | Power surge, compressor, inverter board |
| CH22 | Outdoor | Input current too high | Low supply voltage, overload, board |
| CH23 | Outdoor | DC link voltage too low | Supply voltage drop, inverter board |
| CH24 | Outdoor | High or low pressure switch open | Refrigerant problem, blocked airflow |
| CH25 | Outdoor | Supply voltage too high or too low | Incoming power, wiring |
| CH26 | Outdoor | Compressor position error: it can’t start | Compressor wiring, compressor, inverter board |
| CH27 | Outdoor | Power circuit fault (PSC / reactor) | Inverter board, reactor |
| CH29 | Outdoor | Compressor overcurrent | Restriction, overcharge, compressor |
| CH32 | Outdoor | Compressor discharge temperature too high | Low refrigerant, restriction, sensor |
| CH34 | Outdoor | Pressure too high | Dirty or blocked outdoor coil, overcharge |
| CH35 | Outdoor | Pressure too low | Refrigerant leak, closed service valve |
| CH38 | Outdoor | Low refrigerant detected | Leak, system undercharged at installation |
| CH41 | Outdoor | Compressor discharge pipe sensor open or shorted | Faulty sensor, wiring |
| CH44 | Outdoor | Outdoor air temperature sensor open or shorted | Faulty sensor, wiring |
| CH45 | Outdoor | Outdoor coil pipe sensor open or shorted | Faulty sensor, wiring |
| CH46 | Outdoor | Suction pipe sensor open or shorted | Faulty sensor, wiring |
| CH51 | Outdoor | Too much indoor capacity connected (multi-zone) | Installation or setup |
| CH53 | Outdoor | Outdoor unit not receiving signal from the indoor unit | Same as CH05 |
| CH54 | Outdoor | Power phase reversed or missing (three-phase units) | Electrical work, power outage |
| CH60 | Outdoor | Outdoor board memory error (EEPROM) | Outdoor control board |
| CH61 | Outdoor | Coil temperature too high | Blocked outdoor airflow (cooling), dirty indoor filter (heating) |
| CH62 | Outdoor | Inverter heat sink too hot | Blocked airflow, inverter board |
| CH65 | Outdoor | Heat sink sensor open or shorted | Faulty sensor, board |
| CH67 | Outdoor | Outdoor fan motor locked | Debris, snow or ice, fan motor |
A few LG mini split error codes mean something different on some older models (CH09 and CH10 in particular). If the meaning above doesn’t fit what your unit is doing, check the service information for your exact model number.
The LG mini split error codes homeowners see most
CH05 and CH53: communication error
These are the most common LG mini split error codes. CH05 is reported by the indoor unit and CH53 by the outdoor unit, but both mean the same thing: the two units can’t exchange signals. The first thing to check is whether the outdoor unit has power, because a tripped breaker or a switched-off disconnect box next to the outdoor unit produces exactly this code.
LG splits the advice in two. If the code appeared right after installation, call your installer, because it usually comes from the connecting wiring or piping. If it appeared during normal use, reset the system once, and request service if it comes back. We see the same pattern on other brands, as in our Daikin U4 guide.
CH38: low refrigerant
CH38 is a protective warning: the unit has detected that it’s short of refrigerant and stops to avoid damaging the compressor. A system doesn’t use up refrigerant, so a low charge means a leak or a charge that was never right. LG’s advice is to contact your installer if it appears soon after installation, and otherwise to reset once and call for service if it returns. Adding refrigerant without finding the leak only buys time.
CH61: overheating
In cooling mode, CH61 usually means the outdoor unit can’t get rid of its heat: leaves, a fence, plants or a cover are blocking the airflow, or hot air is being recirculated. In heating mode, LG’s first check is the indoor filter, because the indoor coil works as the hot side in winter. Clear the outdoor unit, clean the filter, reset, and call a technician if it returns.
CH10 and CH67: fan locked
CH10 is the indoor fan and CH67 the outdoor fan. LG’s guidance is to look for debris or snow around the fans and remove it. In winter, ice around the outdoor fan is a common cause; our guide to a heat pump blowing cold air in heat mode explains how normal defrost differs from a unit that’s icing up. If nothing is in the way, the motor or the board needs testing.
CH04: drain problem
CH04 means water isn’t leaving the indoor unit. It shows up mainly on units with a condensate pump, such as ceiling cassettes and ducted units. Check that the drain line’s outlet outside isn’t blocked or frozen and look for water around the unit. The pump and float switch inside need a technician.
CH01, CH02, CH06 and other sensor codes
LG groups CH01, CH02, CH06 and the outdoor sensor codes CH41 to CH48 together: the unit is reading an impossible value from a temperature sensor. LG lists four possible causes: a faulty sensor, a loose or disconnected sensor, a control board error, or a temporary electrical issue. A reset clears the last one. The others need a technician, but a sensor is one of the cheaper repairs on this list.
CH21, CH23, CH26 and CH29: compressor and power
According to LG, these codes point to the outdoor unit’s compressor or circuit board. Possible causes range from a temporary power issue to a faulty compressor, compressor drive or protection circuit. Reset once. If the code returns, don’t keep restarting the unit: repeated starts against a fault can turn a board repair into a compressor replacement.
What to try before calling a technician
These steps cost nothing and cover the LG mini split error codes a homeowner can actually do something about:
- Write down the code and when it appeared: right after installation, after a power outage, or out of nowhere.
- Reset once: remote off, breaker off for five minutes, then back on.
- Check the breakers and the outdoor disconnect. If a breaker trips again, leave it off.
- Clean the indoor filters. It helps with CH61, CH10 and weak heating or cooling.
- Clear the outdoor unit of leaves, snow, ice and anything stacked against it.
- If the system is new, call the installer first. Installation problems are usually theirs to fix.
What fixing LG mini split error codes usually costs
| Repair | Typical cost | Codes it can resolve |
|---|---|---|
| Reset, breaker, filter cleaning | $0 | Any temporary code, CH61, CH10 |
| Diagnostic visit | $60–$200 | All |
| Fan motor | $200–$700 | CH10, CH67 |
| Circuit or control board | $150–$700 | CH05/CH53, CH09, CH21–CH27, CH60 |
| Refrigerant leak repair | $300–$1,200 | CH38, CH35, CH32 |
| Refrigerant recharge after the repair | $150–$450 | CH38 |
| Compressor replacement on a mini split | $1,200–$4,500 | CH26, CH29 if the compressor has failed |
Repair ranges come from Angi’s heat pump repair data and PickHVAC’s mini split cost guide (both May 2026). Before paying for a board or compressor, check whether your system is still under the manufacturer’s or installer’s warranty. If you’re facing a compressor on an older system, compare the quote with what a new system costs in our heat pump installation cost by state data. And if you own another brand, our Mitsubishi mini split error codes list works the same way.
Frequently asked questions
How do I reset LG mini split error codes?
Turn the unit off with the remote, switch off its breaker or unplug it, wait about five minutes and restore power. If the code doesn’t come back, nothing else is needed.
Can I keep using my LG mini split with an error code?
Usually the unit stops on its own to protect itself. If the code clears after a reset and doesn’t return, you can keep using it. If it keeps coming back, have it checked rather than restarting it again and again.
What does CH05 mean on an LG mini split?
The indoor unit isn’t receiving a signal from the outdoor unit. Check that the outdoor unit has power; if it appeared after installation, call your installer.
My LG mini split is blinking but shows no code. What does it mean?
Models without a display show the error by blinking a lamp on the indoor unit. Count the blinks and check your owner’s manual, or give the blink pattern to your technician.
Seen one of the LG mini split error codes that isn’t on this list, or fixed one in a way we haven’t covered? Tell us and we’ll add it.
Sources
- LG USA, [LG Air Conditioner] Guide to Error Codes (February 2026)
- LG USA, How to Troubleshoot Error Codes CH01, CH02, CH06 … CH21, CH23, CH26, CH29 (August 2026)
- LG Canada, Single / Multi-Split Air Conditioner Error Codes
- LG Air Conditioning, Universal Split Systems Fault Codes sheet
- LG, Single Zone Mega Wall Mounted Owner’s Manual
- Angi, Heat Pump Repair Cost (May 2026)
- PickHVAC, Mini Split Running, Service and Repair Cost (May 2026)