LG mini split error code CH04
Drain pump or float switch fault. Also shown as CH 04, CH4.
- TypeFault
- SystemCondensate drain
- Can I fix it?Usually a homeowner fix
What CH04 means on a LG
The float switch reports the condensate level is too high, or the drain pump is not keeping up. The unit stops cooling to avoid an overflow.
On this platform, CH04 is a fault: something has failed or is disconnected and needs diagnosis.
Common causes
- A blocked or kinked condensate drain.
- A drain line without continuous fall.
- A failed drain pump.
- A stuck float switch.
How to fix it yourself
You can almost always clear this yourself with the steps below.
- Confirm water flows from the drain outlet while cooling.
- Clear the drain with a wet/dry vacuum at the outlet.
- Check the drain line for dips.
- If a pump is fitted, check it runs and the float moves freely.
Switch off power at the breaker before opening either unit. Capacitors in the outdoor unit hold a charge for several minutes after power is cut.
When to call a technician
A technician can replace a failed pump or float switch.
Which LG units show CH04
This page applies to LG Art Cool, Standard, Mega and Multi F units. LG's own documentation lists CH04 as "Drain pump or float switch fault", the same definition used across the LG it is built on. If your unit shows a code with a different shape (for example a four-character code, or a plain number), it is from a different table; use the lookup with your exact code.
Where LG shows this code
The indoor display shows CH followed by a number (CH05, CH38). Units without a display blink the indicator lamps in a pattern; the outdoor board LEDs blink the same number. If someone tells you 'CH 5', that is CH05. CH01 to CH12 are indoor-unit faults, CH21 to CH29 are inverter and compressor faults, CH32 to CH38 are refrigerant-side protections, CH40 to CH48 are outdoor sensors, and CH51 to CH73 are outdoor-unit system faults.
Other LG codes
Questions people ask
Can I reset a LG CH04 code myself?
Yes. Turn the system off at the breaker for five minutes, then restart it. If CH04 comes back, the fault is real and needs the checks above.
Is it safe to keep running a LG showing CH04?
The unit will usually refuse to run, or run with reduced output, until the fault is cleared. Repeated resets do not fix anything and can mask a problem that is getting worse.
Do I need a technician for LG CH04?
You can almost always clear this yourself with the steps below. A technician can replace a failed pump or float switch.
Sources
- LG residential split service manuals (error code tables)
Updated September 2026. Codes and definitions vary by model year. If your manual disagrees with this page, your manual wins. Send a correction.