LG Air Conditioner Error 9

⚡ Quick Answer: The LG air conditioner error code 9 indicates a communication failure between the indoor and outdoor units, often due to an EEPROM fault in the indoor... ✅ DIY Fixable

What Does Error 9 Mean?

The LG air conditioner error code 9 indicates a communication failure between the indoor and outdoor units, often due to an EEPROM fault in the indoor unit control board. Symptoms include the unit stopping operation, erratic display behavior, or failure to restart. If this error persists, further inspection or repair may be necessary.

Common Symptoms:

  • Air conditioner stops operating and displays error code 9
  • Unit may fail to start or restart properly
  • Outdoor unit fan may not operate (in some community reports for C9 variant)

Possible Causes

  • EEPROM/EPROM fault in indoor unit control board (medium)

How to Fix Error 9

DIY Fix Basic checks and power reset

  1. Turn off the air conditioner and disconnect power at the circuit breaker.
  2. Wait 5–10 minutes to allow the system to fully power down.
  3. Restore power and restart the air conditioner to see if the error clears.

Technician Only Inspect and replace indoor control board/EEPROM

  1. Confirm the error code using diagnostic interface or LEDs on the indoor unit.
  2. Access the indoor unit control board and perform EEPROM/EPROM diagnostics.
  3. Replace the indoor control board or EEPROM chip if diagnostics confirm memory fault.
  4. Verify correct wiring and firmware revision on replacement components.

Parts needed: Indoor unit control board, EEPROM/EPROM chip

🛑 When to Call a Pro:
  • If error persists after power reset.
  • If air conditioner fails to cool or function normally after basic troubleshooting.
  • If you are not comfortable performing electrical diagnostics or board-level testing.

Next step

Choose the next step for 9

Confirm the diagnosis before ordering. An error code can identify the system involved, but it does not prove that a specific part has failed.

Based on diagnostic data

Most relevant component to inspect

HVAC Control Board

Controls fan, compressor, sensor, and communication functions in the HVAC unit.

Typical part-only price
$90 - $320
DIY difficulty
Hard
Estimated time
45-120 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.

Find a part that fits my model

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.

Model number required

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.

Find a part that fits my model

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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.

Maintenance supply

Air Conditioner Fin Cleaner

For routine cleaning of accessible coil fins when permitted by the manufacturer. Disconnect power and follow product and appliance instructions.

View maintenance supply
Maintenance supply

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.

Find one that fits my model

Affiliate disclosure: As an Amazon Associate I earn from qualifying purchases. Recommendations are based on routine-care relevance, not commission rate.

Technical Specifications

wattage 1500W
component Control Board
resistance 5-15 ohms
part_number LG 6711A20045A
voltage_rating 220V AC

Common Questions

What does 9 error mean on lg air conditioner?

Error 9 means there is a communication failure between the indoor and outdoor units, often caused by an EEPROM fault.

Can I fix lg air conditioner 9 error myself?

Yes, you can perform basic checks and reset the power to potentially clear the error.

How much does it cost to fix 9 error?

Repair costs for error 9 range from $150 to $400, including parts and labor.

When should I call a technician for 9?

Call a technician if the error persists after a power reset or if you're uncomfortable with electrical diagnostics.

Sources & References

Data last verified: 2026-07-26

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