LG Air Conditioner Error 31
⚡ Quick Answer: The LG air conditioner error code 31 indicates a communication failure between the indoor and outdoor units. This issue can manifest as the unit stopp... ✅ DIY Fixable
What Does Error 31 Mean?
The LG air conditioner error code 31 indicates a communication failure between the indoor and outdoor units. This issue can manifest as the unit stopping cooling and displaying the CH31 error. Common causes include high-pressure sensor abnormalities and problems with the outdoor unit's temperature sensor. To troubleshoot, ensure that filters are clean and airflow to the outdoor unit is unobstructed. If the error persists, further inspection may be needed.
Common Symptoms:
- Unit stops cooling and displays CH31
- May occur after temperature irregularities or sensor issues
- Outdoor unit may overheat or show abnormal temperature behavior
Possible Causes
- High pressure/pressure sensor abnormality (medium)
- Outdoor unit temperature sensor fault or abnormal readings (medium)
How to Fix Error 31
DIY Fix Basic checks and reset
- Turn off the air conditioner and disconnect from power (unplug or circuit breaker)
- Wait about 5 minutes, then restore power and restart the unit
- Ensure **filters are clean** and outdoor unit ventilation is unobstructed to allow proper airflow
Technician Only Service inspection for pressure and sensors
- Check refrigerant system pressure and high‑pressure safety switch operation
- Inspect outdoor and indoor temperature sensors for correct readings and continuity
- Clean or replace any faulty sensors or thermistors
- Verify no blockages in outdoor unit fins or airflow paths
Parts needed: refrigerant pressure sensors, temperature sensors/thermistors, cleaning tools
- CH31 persists after reset and basic cleaning
- Air conditioner fails to cool properly
- Unusual noises or smells accompany the error
- Visible signs of refrigerant leak or overheating
Next step
Choose the next step for 31
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
Temperature Sensor
Monitors the internal temperature to ensure correct operation and prevent overheating.
- Typical part-only price
- $15 - $35
- DIY difficulty
- Easy
- Estimated time
- 15-30 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.
Thermistor
Measures precise temperature changes and sends resistance feedback to the control board.
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 Module |
| resistance | N/A |
| part_number | LG 6710A20024D |
| voltage_rating | 230V AC |
Common Questions
What does 31 error mean on lg air conditioner?
Error 31 indicates a communication failure between indoor and outdoor units, causing the unit to stop cooling.
Can I fix lg air conditioner 31 error myself?
Yes, you can try basic checks like resetting the unit and cleaning filters to resolve the issue.
How much does it cost to fix 31 error?
Repair costs range from $100 to $400, depending on parts and regional service rates.
When should I call a technician for 31?
Call a technician if the error persists after reset, if cooling fails, or if you notice unusual noises or smells.
Sources & References
Data last verified: 2026-07-26
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