Draft preview

This page is auto-generated from scraped sources and has not been manually verified against the service manual yet.

Lg Mini Split H21 Error Code

Updated 2026-08-29 · review status: draft Draft - unverified

Quick answer

H 21 means the outdoor inverter power module or compressor drive has reported a fault. LG's support table points to compressor or inverter PCB failure, so this is not a homeowner repair. Advisory Technician Breadth evidence 6 published catalog models on its documented product line. Safe first check Turn the system off and power cycle once at the breaker if you can do that safely. If.

Severity: high · DIY difficulty: intermediate

Safety

TBD - must be written per-code before publish

What H21 means

H 21 means the outdoor inverter power module or compressor drive has reported a fault. LG's support table points to compressor or inverter PCB failure, so this is not a homeowner repair. Advisory Technician Breadth evidence 6 published catalog models on its documented product line. Safe first check Turn the system off and power cycle once at the breaker if you can do that safely. If.

Causes, ranked

  1. Causes not yet documented — verify against the service manual.

Commonly searched as: "lg h21" · "lg error code h21" · "lg air conditioner h21"

Sources

  • SplitAtlas manual-sourced reference — verified 2026-08-29