LG air conditioner CH38 code: low refrigerant protection (mini-split)

On LG mini-splits, CH38 appears when the system detects that the refrigerant level is low, and it stops to protect the compressor. A leak, often at a pipe connection made during installation, is the usual cause, though LG notes power problems can trigger it briefly.

Likely causes

Listed from most to least common.

1. Refrigerant leak at a flare connection, often from installation
2. Leak in the indoor or outdoor coil or line set
3. System not charged correctly when installed, especially with long line sets
4. Temporary electrical instability causing a false reading
5. Sensor or valve fault in the outdoor unit

How to fix the CH38 code

Unplug the air conditioner or switch it off at the breaker before removing any panel or filter.

1. 1

   Step 1: Reset the power once

   Switch off the unit's breaker, wait 5 minutes and switch it back on. LG says unstable power can cause a temporary CH38.

2. 2

   Step 2: Note when it started

   If CH38 appeared soon after installation or after the unit was moved, contact your installer first. LG says this often means a loose connection or a leak from the install.

3. 3

   Step 3: Stop using the unit if it returns

   If CH38 comes back after the reset, turn the unit off. Running it low on refrigerant can damage the compressor.

When to call a technician

Refrigerant work needs a licensed HVAC technician. They will find and fix the leak, pull a vacuum and recharge the system. Never add refrigerant yourself.

A typical repair for this code costs $300–$1500 in the US, including parts and labor. Prices vary by area and model.

Models this applies to

• Ductless mini-splits (wall-mounted and Art Cool)
• Multi-zone mini-split systems
• Window air conditioners
• Portable air conditioners

Codes can differ slightly between models. Your owner's manual is the final word and is available from LG support.

Common questions