LG mini split error code CH09

Common causes

• A surge event.
• A failed board.
• A replacement board not programmed.

How to fix it yourself

Do the reset and the visual checks, but the underlying repair needs a technician with a meter and the service manual.

1. Reset the system: switch the breaker (or the outdoor disconnect) off, wait a full five minutes so the boards fully discharge, then switch it back on and restart from the remote.
2. If the code comes straight back after a reset, the fault is real and not a glitch.

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

Board replacement or reprogramming.

Which LG units show CH09

This page applies to LG Art Cool, Standard, Mega and Multi F units. LG's own documentation lists CH09 as "Indoor unit EEPROM error", 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

Same part of the system as CH09:

All LG error codes