LG Air Conditioner
LG AC CH05 error
Communication error (indoor ↔ outdoor unit)
Try a reset once. If it comes back, a trained technician should repair it.
Also shown as: 05
What it means
Two parts of the appliance (indoor ↔ outdoor unit) have stopped talking to each other. A loose wire, low voltage or a faulty board can cause this.
Common causes
- Loose or damaged connecting / signal wire
- Low or fluctuating voltage, or a faulty stabilizer
- Water, insects or rust on terminals
- Faulty control board
Try this at home first
Tick each step as you go
When to call a technician
If it comes back, a technician should check the connecting cable and boards. Do not open the outdoor unit yourself — it has high voltage.
Safety first
Always switch off at the wall socket or MCB before touching any part. Do not open the outdoor unit, control boards or gas pipes yourself — they carry high voltage and pressure.
Frequently asked questions
What does CH05 mean on a LG Air Conditioner?
Communication error (indoor ↔ outdoor unit). Two parts of the appliance (indoor ↔ outdoor unit) have stopped talking to each other. A loose wire, low voltage or a faulty board can cause this.
Can I fix LG Air Conditioner error CH05 myself?
You can try a reset first: Switch off at the MCB for 5–10 minutes, then switch on. If the code returns, call a technician.
Is it safe to keep using the Air Conditioner with CH05?
Avoid repeated restarts; running with this fault can cause more damage.
Other LG AC codes
Sources
We write every explanation in our own words from these references.
Last checked: 2026-10-20