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

  1. Turn off the air conditioner and disconnect from power (unplug or circuit breaker)
  2. Wait about 5 minutes, then restore power and restart the unit
  3. Ensure **filters are clean** and outdoor unit ventilation is unobstructed to allow proper airflow

Technician Only Service inspection for pressure and sensors

  1. Check refrigerant system pressure and high‑pressure safety switch operation
  2. Inspect outdoor and indoor temperature sensors for correct readings and continuity
  3. Clean or replace any faulty sensors or thermistors
  4. Verify no blockages in outdoor unit fins or airflow paths

Parts needed: refrigerant pressure sensors, temperature sensors/thermistors, cleaning tools

🛑 When to Call a Pro:
  • 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

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: 2026-01-11

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