Short answer: LG mini splits show faults as a code starting with CH on the display, or as a blinking light. LG's own advice is to write the code down, turn off power for about five minutes, and restart. If the same code returns, stop using the unit and call for service. Do not take the unit apart.
What LG tells owners to do first
LG's support page for air conditioner error codes says an error can be temporary, caused by power instability or other electrical factors. Its reset steps are:
- Unplug the unit or turn off its circuit breaker.
- Wait about five minutes.
- Plug it back in or turn the breaker on.
- See whether the code is gone.
LG says that if the same code or symptoms persist, a technician needs to inspect it. Its sensor-code page adds a warning: do not disassemble the unit or replace internal parts yourself, because of fire, shock and injury risk. It also says that if a code returns after a reset, stop using the product and request service.
If the code goes away and the unit runs normally, LG says you can keep using it. If it comes back, stop.
Codes LG explains
These are the codes LG's U.S. support pages describe. LG notes that its guides cover many models, so some codes display differently on yours.
| Code | What LG says |
|---|---|
| CH04 | Drainage problem. Water inside the indoor unit is not draining |
| CH05, E0, CH53 | Communication error between indoor and outdoor units |
| CH07 | Mode conflict on multi-unit systems. One unit is set to heat while another is on cool or dry |
| CH10, E6 | Indoor fan problem |
| CH67, EF | Outdoor fan problem |
| CH38, F4 | Low refrigerant protection |
| CH54 | Reverse phase detected, which can follow a power outage or electrical work |
| CH61 | Overheating protection. Outdoor unit too hot in cooling, or indoor unit too hot in heating. May also show as P4, P6, P7, P8 or CH34 |
| CH66 | Communication or piping connection problem between indoor and outdoor units |
| CH01, CH02, CH06, CH12, CH41 to CH48, E1, E2, E3, E7, E8, F2, F3 | Sensor related problems |
| CH21, CH23, CH26, CH29, E9 | Outdoor compressor or circuit board problem |
LG also says that if your code is not on its list, ask for a service technician, because fixing it yourself may be difficult.
What you can check yourself
Look at the display and write the code down or take a photo. Then go through these steps in order and stop as soon as something does not match.
Only a few codes have safe owner checks:
- CH04 (drainage). Look for a kinked or blocked drain hose and a water leak. See mini split drain line and mini split leaking water. LG says that for ceiling units the fix is a reset, then service if it persists.
- CH07 (mode conflict). Set every indoor unit on the system to the same kind of mode. LG says cool and dry can run together, heat cannot run with them. Fan and air purification modes are fine anytime.
- CH61 and its P codes (overheating). LG's list of checks: make sure the outdoor unit has airflow and nothing is stacked around it, and clean the indoor filter. See how to clean a mini split. LG says CH61 will not clear on its own. You need to power cycle it.
- CH10, E6, CH67, EF (fan). LG says to check for debris or snow around the fan areas. Look from the outside only. If nothing is visible, service is needed.
When to call a technician
Call LG or a technician when:
- A code returns after the five minute reset
- The code is a sensor, compressor, circuit board, communication or refrigerant code
- The code appeared right after installation or moving the unit (LG says to contact the installer for CH05, CH66 and CH38)
- A breaker keeps tripping
For no code but weak cooling or heating, read mini split not cooling or mini split not heating.
If you are unsure whether the display shows a setting or an alarm, compare it with the LG remote symbols guide before treating it as a fault code.
Sources
- LG USA Support: Guide to Error Codes (updated 02/23/2026)
- LG USA Support: Troubleshooting sensor and compressor codes (updated 08/20/2026)
Follow your unit's own manual. This is general information.
