LG Mini Split H237 Error Code

Updated 2026-08-29 · review status: manual-verified · reviewed by MiniSplitDecoder Editorial Team Last verified: 2026-08-29

Check your model first

The source record does not specify an exact model family.

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

Quick answer

CH237 points to an indoor/outdoor connection problem and can also occur when the outdoor unit has no power. Post-2021 LG models display three-digit CH codes. Check power and wiring visually, reset once, and call a technician if it returns.

Severity: medium · DIY difficulty: intermediate

Safety

Stop at checking that the outdoor unit has power, a visual cable check, and one reset. Do not open either unit or test the communication line with a meter. Technician-only.

What H237 means

H237 (displayed as CH237) points to an indoor/outdoor connection problem and can also occur when the outdoor unit has no power. LG explains that post-2021 models can display three-digit CH codes in sequence, such as CH 237.

Causes, ranked

  1. 1. Outdoor unit has no power (tripped breaker, disconnected disconnect, outage) common DIY

    Check: Check that the outdoor unit's breaker/disconnect is on and the outdoor fan/compressor area shows no signs of power loss.

    Fix: Restore power if safely possible; otherwise schedule service.

  2. 2. Indoor/outdoor communication wiring damage or loose terminal common DIY

    Check: Visually check the interconnecting cable at both ends for damage or loose strain relief (do not disconnect live wires).

    Fix: If damage is visible, schedule service; otherwise power cycle once and retest.

  3. 3. Transient communication fault that clears after one reset occasional DIY

    Check: Power cycle both indoor and outdoor units once.

    Fix: If CH237 returns, stop resetting and schedule service.

  4. 4. Indoor or outdoor PCB communication-circuit fault rare pro only

    Check: Board-level diagnosis only.

    Fix: Technician: diagnose both PCBs; replace the faulty board.

Related codes

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

LG H238 · LG H22 · LG H24

Commonly searched as: "lg h237" · "lg error code h237" · "lg air conditioner h237"

Sources

Related Mini Split guides

Mini-Split Communication Error: DIY Checks · Mini-Split Flashing Light Decoder: Blink Patterns · How to Reset a Mini-Split After a Power Outage