LG Air Conditioner Error 12
⚡ Quick Answer: The LG air conditioner error 12 indicates a communication failure between the indoor and outdoor units. This error is often signaled by the display fl... ✅ DIY Fixable
What Does Error 12 Mean?
The LG air conditioner error 12 indicates a communication failure between the indoor and outdoor units. This error is often signaled by the display flashing the code, which can cause the unit to stop operating or fail to start normally. If this issue persists, it may require inspection and repair of the communication wiring and components.
Common Symptoms:
- Error code 12 (sometimes shown as CH12) displayed on unit
- Unit may stop operating or fail to start normally
- Possible loss of communication between indoor and outdoor units
Possible Causes
- Communication failure between indoor and outdoor unit (medium)
How to Fix Error 12
DIY Fix Check power and basic connections
- Turn off the air conditioner and disconnect power for a few minutes.
- Ensure the main power supply and circuit breaker aren’t tripped.
- Check that both indoor and outdoor units are powered and securely connected.
Technician Only Inspect and repair communication wiring and components
- Check communication wiring between indoor and outdoor units for damage, loose connections, or corrosion.
- Test signal receiver and transmitter circuits on indoor and outdoor PCBs.
- Verify installation quality and alignment of units to electrical specifications.
- Replace any faulty communication harness or control board component as needed.
Parts needed: Communication wiring harness, Indoor unit control board, Outdoor unit control board
- If error persists after power reset and basic checks
- If wiring inspection reveals damage beyond basic user repair
- If unit repeatedly fails to communicate between indoor/outdoor units
Next step
Choose the next step for 12
Confirm the diagnosis before ordering. An error code can identify the system involved, but it does not prove that a specific part has failed.
Most relevant component to inspect
Wiring Harness
Connects controls, sensors, motors, and other electrical components inside the appliance.
- Typical part-only price
- $20 - $120
- DIY difficulty
- Medium
- Estimated time
- 30-90 mins
Where can I find the model number?
Check the rating label around the door, lid, frame, rear panel, or inside the appliance cabinet. Use the complete model number, including suffixes.
Verify the complete model and part number on the retailer's compatibility page before ordering.
Other parts options
Check related components first; use model search as a fallback.
HVAC Control Board
Controls fan, compressor, sensor, and communication functions in the HVAC unit.
Model-compatible Air Conditioner parts
Enter the complete model number to browse compatible replacement parts. This is a model-based parts search, not a diagnosis that a specific component failed.
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Optional routine care
Maintenance supplies
These products support cleaning or routine upkeep. They are separate from the possible repair components above and are not claimed to fix this error code or symptom.
Air Conditioner Fin Cleaner
For routine cleaning of accessible coil fins when permitted by the manufacturer. Disconnect power and follow product and appliance instructions.
Model-Compatible Washable AC Filter
A reusable filter option only where the appliance supports one. Match the full model, dimensions, and filter specification.
Compatibility check required: use the complete appliance model and compare the existing filter, bag, or specification before ordering.
Affiliate disclosure: As an Amazon Associate I earn from qualifying purchases. Recommendations are based on routine-care relevance, not commission rate.
Technical Specifications
| wattage | 2000W |
|---|---|
| component | Control Board |
| resistance | 0-5 ohms |
| part_number | LG 6711A20066B |
| voltage_rating | 220V AC |
Common Questions
What does 12 error mean on lg air conditioner?
Error 12 indicates a communication failure between indoor and outdoor units.
Can I fix lg air conditioner 12 error myself?
Yes, you can check power and connections, and reset the unit.
How much does it cost to fix 12 error?
Repair costs vary by region, typically including technician fees and parts.
When should I call a technician for 12?
Call if the error persists after basic checks or if wiring is damaged.
Sources & References
- LG Air Conditioner Guide to Error Codes (official)
Data last verified: 2026-07-26
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