LG Air Conditioner Error 27

⚡ Quick Answer: The LG air conditioner error code 27 (CH27) indicates a communication failure between the indoor and outdoor units, often due to an inverter over-curr... ✅ DIY Fixable

What Does Error 27 Mean?

The LG air conditioner error code 27 (CH27) indicates a communication failure between the indoor and outdoor units, often due to an inverter over-current fault. This protective shutdown prevents the compressor from engaging properly, leading to operational failure. Common symptoms include the outdoor unit running briefly before stopping and the display panel showing the error code. This issue is typically linked to electrical irregularities in the inverter/compressor circuit.

Common Symptoms:

  • AC stops operation and displays CH27 on panel
  • Outdoor unit runs briefly and stops
  • Compressor fails to engage properly or system trips shortly after start

Possible Causes

  • Inverter/IGBT over‑current fault (medium)
  • Outdoor unit compressor electrical fault or overload (medium)

How to Fix Error 27

DIY Fix Basic user actions to attempt before service

  1. Turn off the AC and disconnect power at the breaker or power plug
  2. Wait at least 5–10 minutes to allow the system to fully reset
  3. Restore power and restart the unit to see if error clears

Technician Only Professional diagnosis and repair

  1. Measure outdoor unit inverter and compressor current levels
  2. Inspect inverter PCB and IGBT components for damage or overheating
  3. Check outdoor unit wiring integrity and insulation
  4. Perform compressor electrical performance tests and verify no overload conditions

Parts needed: inverter PCB/IGBT module, compressor motor and windings, outdoor unit wiring harness

🛑 When to Call a Pro:
  • If CH27 repeats after power reset
  • If outdoor unit isn’t running normally or makes unusual noise
  • If any wiring appears damaged or overheated

Next step

Choose the next step for 27

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

Other parts options

Check related components first; use model search as a fallback.

Possible related component

Wiring Harness

Connects controls, sensors, motors, and other electrical components inside the appliance.

$20 - $120 · Medium · 30-90 mins

Check fit & price
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.

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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

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Technical Specifications

wattage 1500W
component Control Board
resistance 5-10 ohms
part_number LG 6711A20045D
voltage_rating 230V AC

Common Questions

What does 27 error mean on lg air conditioner?

Error 27 indicates a communication failure, linked to an inverter fault, causing the unit to stop working.

Can I fix lg air conditioner 27 error myself?

Yes, try resetting the unit by turning it off and disconnecting power for 5-10 minutes.

How much does it cost to fix 27 error?

Repair costs for error 27 range from $200 to $800, depending on parts and labor.

When should I call a technician for 27?

Call a technician if the error reoccurs after a reset or if you notice unusual sounds or damaged wiring.

Sources & References

Data last verified: 2026-07-26

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