LG CH21 Error Code: DC peak error or IPM fault
Updated October 2026 · Sourced from LG documentation
🛑 Turn it off and call a licensed pro
DC peak error or IPM (inverter power module) fault. The compressor DC voltage was too high.
Is it safe to keep running? No. Turn it off and get it checked. Compressor and inverter faults need a licensed technician. Do not open the outdoor unit.
CH21 at a glance
| Code / how it shows | Meaning | Applies to |
|---|---|---|
| CH21 Also: 21 On North American units, shown as blinking indicator LEDs (LED1 2 blinks, LED2 1 blink); on other markets shown as the number 21 | DC peak error or IPM fault | LG single-split and multi-split air conditioners (North America LED blink code chart) |
Check this first
Only steps a homeowner can do safely. Do not open electrical panels or the burner area.
- Turn the power off or trip the circuit breaker for the unit, wait about 5 minutes, then turn it back on.
🛑 Stop and call a licensed pro if
- Compressor and inverter faults need a licensed technician. Do not open the outdoor unit.
- Any code pointing to refrigerant, the compressor, high pressure or the outdoor unit board. Refrigerant work legally needs a certified technician.
- Burning smell, sparks, or a breaker that trips again after a reset.
- Water leaking from the indoor unit that does not stop after the drain is clear.
Safe first steps for any LG code
- Write down the exact code and how it shows (remote display or number of lamp blinks). Similar codes mean different things on different series.
- Turn the system off at the remote, switch off the breaker or disconnect for the unit, wait a few minutes, then turn it back on.
- Clean or replace the indoor unit air filters, and make sure nothing blocks the indoor or outdoor unit.
- Check that the condensate drain line is not blocked or kinked where you can see it.
- Replace the remote controller batteries if the display is dim or the unit does not respond.
Source: LG Single / Multi-Split Air Conditioner Error Codes (LG Canada help library), Error Code Chart. Codes are series-specific, so your unit's own manual is the final word. Reviewed October 2026.
Shaun Cain · Certified HVAC & Refrigeration Technician · Ask an HVAC technician
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