LG Air Conditioner Error 28
⚡ Quick Answer: The LG air conditioner error code 28 signifies a communication failure between the indoor and outdoor units. This issue may prevent the unit from oper... ⚠️ Difficulty Varies
What Does Error 28 Mean?
The LG air conditioner error code 28 signifies a communication failure between the indoor and outdoor units. This issue may prevent the unit from operating correctly and often results in a loss of cooling or heating function. It can stem from problems with the inverter DC link or electrical faults in the outdoor unit, leading to disrupted signals between the units.
Common Symptoms:
- Display of error code "28" on indoor unit or remote
- Air conditioner stops operation shortly after start
- Possible loss of cooling/heating function due to fault detection
Possible Causes
- Indoor–outdoor unit communication fault (medium)
- Inverter/DC link high voltage or electrical fault in outdoor unit (medium)
How to Fix Error 28
DIY Fix Basic user checks and restart
- Turn off the unit and disconnect power at the breaker for 5–10 minutes
- Reconnect power and restart to see if the error clears
- Check that the indoor and outdoor units are correctly powered and that wiring/connectors visible to the user are secure
- Ensure outdoor unit is not obstructed and filters are clean
Technician Only Technician diagnosis of communication/inverter fault
- Use service diagnostic tools to read detailed fault logs from the indoor and outdoor boards
- Verify communication wiring integrity between indoor and outdoor units (connector continuity, no corrosion)
- Measure DC link and supply voltages to verify inverter circuit health
- Test/reland control boards if communication or inverter electronics faults are present
Parts needed: communication cable, indoor control board, outdoor inverter module/DC link components
- Error persists after power cycle and basic checks
- Repeated occurrences of error 28
- Any unusual noises, smells, or inability to operate after reset
Next step
Choose the next step for 28
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
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.
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-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.
Affiliate disclosure: As an Amazon Associate I earn from qualifying purchases. We may earn a commission from other qualifying purchases or service requests made through links on this page, at no additional cost to you. Recommendations are based on repair relevance, not commission rate.
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 | N/A |
|---|---|
| component | Communication Wire |
| resistance | N/A |
| part_number | LG 6711A20045A |
| voltage_rating | 220V AC |
Common Questions
What does 28 error mean on lg air conditioner?
Error 28 indicates a communication failure between indoor and outdoor units, preventing operation.
Can I fix lg air conditioner 28 error myself?
Yes, you can try power cycling the unit and checking connections before seeking professional help.
How much does it cost to fix 28 error?
Repair costs for error 28 range from ¥20,000 to ¥80,000+, depending on parts and labor.
When should I call a technician for 28?
Call a technician if the error persists after resetting, recurs frequently, or if you notice unusual sounds or smells.
Sources & References
- LG Air Conditioner Guide to Error Codes (official)
Data last verified: 2026-07-26
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