LG Mini Split H27 Error Code

Updated 2026-08-30 · review status: manual-verified · reviewed by MiniSplitDecoder Editorial Team Last verified: 2026-08-30

Check your model first

  • SplitAtlas (LG support table, Mega R-32)
  • Snowflake Aircon / Cool Aircon SG (wall-mounted rows)
  • HVAC-Boss (CH27/29 group)

Match the model on your equipment label to the linked manufacturer documentation. The same code can mean different things across model families.

Quick answer

LG H27/CH27 means an inverter PSC/PFC overcurrent fault - the outdoor power-factor-correction or power-stage circuit detected excessive current and shut down. Reset once at the breaker; if H27 returns or the breaker trips, leave the system off. Inverter-board and power-circuit work is technician-only.

Severity: high · DIY difficulty: easy

Safety

Stop at the breaker power-cycle and any plug-accessible checks (filters, remote settings, visible wiring). The outdoor unit's capacitor holds a lethal charge and the refrigerant circuit is both pressurized and (on R-32 units) flammable — opening panels or servicing the sealed system is licensed-technician work (EPA 608).

What H27 means

H27 (CH27) means an inverter PSC (prospective short circuit / power-stage) or PFC (power-factor correction) overcurrent fault: current between the AC input and DC converter circuit exceeded the safe limit. LG's support table (per SplitAtlas) reads 'PSC/PFC overcurrent - overload operation or damaged internal PCB components'; Singapore code references describe 'PSC fault; inverter compressor converter current too high' and 'inverter current irregularity (PSC/reactor circuit fault)'. Generic blogs sometimes generalize it as board-internal or 'compressor virtual current' errors.

Code meaning varies by series

  • SplitAtlas (LG support table, Mega R-32): CH27 = PSC/PFC overcurrent - overload operation or damaged internal PCB components
  • Snowflake Aircon / Cool Aircon SG (wall-mounted rows): CH27 = PSC fault; inverter compressor converter current too high between AC and DC converter circuit; reactor circuit fault
  • HVAC-Boss (CH27/29 group): CH27 = inverter compressor overcurrent related to the DC link / main power circuitry

First checks before service

This page currently documents the safe reset triage. If the code returns, use the linked source manual or a qualified technician for code-specific diagnosis.

  1. 1. One-time fault event (power disturbance or transient sensor reading) common DIY

    Check: Power-cycle at the breaker/disconnect (or unplug for CPAP), restore, and run the system while watching for the code.

    Fix: If the code does not return after a full run cycle, the fault was transient — monitor, no repair needed.

  2. 2. Fault persists after a clean reset occasional pro only

    Check: If the code returns immediately or every session, note the conditions (startup, heating, after rain).

    Fix: A persisting code points at the component the manual assigns to this code — that repair is technician territory.

Related codes

Cross-references for the same fault family, by brand:

LG H21 · LG H23 · LG H26

Commonly searched as: "lg h27" · "lg error code h27" · "lg air conditioner h27"

Sources

Related Mini Split guides

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