LG AC Error Code CH05: Causes, Fixes, and How to Reset the Error

What Does LG AC Error Code CH05 Mean?

If your LG air conditioner shows error code CH05, it means there is a communication failure between the indoor unit and the outdoor unit.

Modern LG split air conditioners rely on electronic signals exchanged between the indoor and outdoor components. When this connection is interrupted or fails, the system cannot operate normally and displays CH05.

This error is commonly seen in LG inverter split air conditioners.

Common Causes of LG AC Error Code CH05

Several issues can trigger the CH05 error message.

1. Loose or Damaged Communication Wiring

The indoor and outdoor units are connected through communication wires. If these wires become loose, damaged, or disconnected, the units cannot exchange signals properly.

This is one of the most common reasons for CH05.

2. Power Supply Issues

If either the indoor unit or outdoor unit experiences power fluctuations or unstable voltage, communication between them may fail.

3. Faulty PCB (Control Board)

Both AC units have printed circuit boards (PCBs) that manage system operations. If one of these boards develops a fault, the communication signal may stop.

4. Incorrect Installation

Improper installation, such as incorrect wiring connections, can also lead to this error.

How to Fix LG AC Error Code CH05

You can try the following basic troubleshooting steps.

Step 1: Turn Off the Air Conditioner

Switch off the AC using the remote control.

Step 2: Disconnect the Power Supply

Turn off the main power supply or circuit breaker connected to the AC.

Step 3: Wait for 10–15 Minutes

Allow the system to completely reset.

Step 4: Turn the AC Back On

Restore the power supply and restart the air conditioner.

Sometimes the error disappears after a reset if it was caused by a temporary communication glitch.

When to Call a Technician

If the CH05 error continues to appear, professional servicing is recommended.

A technician may need to:

• Inspect the communication wiring

• Check indoor and outdoor PCB boards

• Test the power supply connections

• Repair or replace faulty components

Since this issue often involves electrical parts, it is safer to let a qualified technician handle the repair.

Tips to Prevent CH05 Error

You can reduce the chances of this error by maintaining your air conditioner properly.

Helpful practices include:

• Ensure the AC is installed by a professional

• Schedule regular servicing

• Protect the system from power fluctuations

• Use a voltage stabilizer if needed

Routine maintenance helps prevent electrical and communication issues.

Final Thoughts

The LG AC error code CH05 typically indicates a communication problem between the indoor and outdoor units. While a simple reset can sometimes resolve the issue, persistent errors usually require inspection of wiring or control boards.

Addressing the problem early helps prevent further damage and ensures your air conditioner continues to run efficiently.

Read More:

LG AC error code CH38

LG AC error code CH67

LG AC error code CH21

LG AC error code CH10