DIY HVAC Tools

LG mini split error code CH29

Compressor over-current. Also shown as CH 29, CH29.

  • TypeProtection
  • SystemCompressor / inverter
  • Can I fix it?Technician job

What CH29 means on a LG

Current in the compressor windings exceeded the limit.

On this platform, CH29 is a protection: the system stopped or throttled itself to prevent damage; many clear on their own once conditions return to normal.

Common causes

  • A blocked outdoor coil or failed fan.
  • Low supply voltage.
  • A failing compressor.
  • An overcharge.

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. Look at the outdoor unit: clear leaves, cottonwood fluff, snow or ice from the coil and make sure the fan can spin freely and nothing is stacked against the cabinet.
  2. If you own a multimeter and are comfortable using it, measure the supply voltage at the outdoor unit's L1 and L2 terminals with the unit running. A 230 V system should read roughly 208 to 253 VAC.
  3. 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.

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

Technician check of compressor current and charge.

Which LG units show CH29

This page applies to LG Art Cool, Standard, Mega and Multi F units. LG's own documentation lists CH29 as "Compressor over-current", 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 CH29:

CH21Inverter DC peak (IPM over-current)CH26DC compressor position error (start failure)CH32Discharge temperature too highCH62Inverter heat sink temperature too high
CH01Indoor air (room) temperature sensor fault (open or short circuit)CH02Indoor inlet pipe temperature sensor fault (open or short circuit)CH03Communication error with the wired remote controllerCH04Drain pump or float switch faultCH05Communication error between indoor and outdoor unitsCH06Indoor outlet pipe temperature sensor fault (open or short circuit)CH07Operating mode conflict (multi-split)CH09Indoor unit EEPROM error

All LG error codes

Questions people ask

Can I reset a LG CH29 code myself?

Yes. Turn the system off at the breaker for five minutes, then restart it. If CH29 comes back, the fault is real and needs the checks above.

Is it safe to keep running a LG showing CH29?

Not repeatedly. A protection code means the unit stopped itself to prevent damage, and resetting it over and over can turn a cheap repair into a compressor failure. Reset once, check the basics, and stop if it returns.

What will a technician check for CH29?

Technician check of compressor current and charge. Ask for the measurements, not just a parts quote.

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.