ERROR CODE EXPLAINED
LG Air Conditioner
LG Air Conditioner CH66 Error Code
What it means
CH66 indicates a communication-line or piping-connection problem between the indoor and outdoor units.
Try this first
- If it appeared after installation or relocation, contact the installation technician to inspect the connections.
- If it appeared during normal use, unplug the unit or turn off its breaker for about 5 minutes, then restore power.
- If the code remains, arrange service.
Can I keep using it?Follow the manufacturer checks that match the condition shown by the appliance; model-specific details can vary.
Repair usually required?If the manufacturer directs the issue to service or the listed checks do not clear it, arrange professional appliance service.
If the error keeps returning
Use the linked official manufacturer support article for the exact source guidance and model-specific details.
Official source
Troubleshooting information verified against manufacturer support documentation.
View manufacturer support page →Safety note:ApplianceSignal provides general troubleshooting information. Always follow the appliance manufacturer's safety instructions and disconnect power when required.