Lg Air Conditioner Error 4

⚡ Quick Answer: The LG air conditioner error 4 indicates a communication failure between the indoor and outdoor units, often linked to an exhaust temperature sensor m... ✅ DIY Fixable

What Does Error 4 Mean?

The LG air conditioner error 4 indicates a communication failure between the indoor and outdoor units, often linked to an exhaust temperature sensor malfunction. Symptoms include the unit not responding, stopping cooling or heating, and briefly running before shutting off. This error typically appears shortly after startup or during operation.

Common Symptoms:

  • Error displayed shortly after startup or during operation
  • Unit may stop cooling or heating when code appears
  • System may run briefly then shut off

Possible Causes

  • Exhaust temperature sensor fault or related sensor malfunction (medium)

How to Fix Error 4

DIY Fix Basic verification and restart

  1. Turn off the AC and disconnect power
  2. Wait for at least 5–10 minutes
  3. Reconnect power and restart the system to see if the code reappears

Technician Only Inspect and potentially replace temperature/exhaust sensor

  1. Access the internal sensors (exhaust/temperature thermistor) with power off
  2. Check sensor connections for corrosion or loose contacts
  3. Measure sensor resistance/response against expected values
  4. Replace the faulty sensor if readings are outside expected range

Parts needed: Temperature/exhaust sensor (thermistor), Associated wiring/connectors

🛑 When to Call a Pro:
  • If error persists after power cycle and sensor inspection
  • If multiple codes appear simultaneously
  • If there are signs of electrical damage or burning smell

Technical Specifications

wattage 2000W
component Control Board
resistance 10-20 ohms
part_number LG 6711A20045B
voltage_rating 220V AC

Common Questions

What does 4 error mean on lg air conditioner?

Error 4 indicates a communication failure, often tied to a malfunctioning temperature sensor.

Can I fix lg air conditioner 4 error myself?

Yes, you can try restarting the unit by powering it off for 5-10 minutes.

How much does it cost to fix 4 error?

The estimated repair cost ranges from ¥5,000 to ¥25,000, depending on the region.

When should I call a technician for 4?

Call a technician if the error persists after a power cycle or if you notice multiple error codes.

Sources & References

Data last verified: 2026-01-10

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