LG Refrigerator Error Code Er rt — Room Temperature Sensor Error
What this means
The Er rt error code indicates the refrigerator's ambient (room) temperature sensor is not reading correctly. This sensor monitors the temperature of the room where the refrigerator is located and helps the control system optimize compressor and fan operation. A faulty sensor can lead to inefficient cooling or overcooling.
Alternate codes: rt
Step-by-step fix
3 stepsPower cycle the refrigerator
Unplug the refrigerator for 10 minutes and plug it back in. Check if the error clears — a temporary sensor glitch can cause a false reading.
Locate the room temperature sensor
The room temperature sensor is typically located on the outside of the refrigerator cabinet, often near the bottom rear or behind the lower grille. It measures the ambient air temperature around the unit.
Test and replace the sensor
Unplug the refrigerator. Disconnect the sensor and test with a multimeter. At room temperature (approximately 77°F / 25°C), the sensor should read approximately 5,000 ohms. Replace if the reading is abnormal.
Make sure the replacement sensor is positioned to measure ambient air, not heat radiated from the compressor.
When to call a professional
If the sensor tests normally but the error persists, the main control board may have a faulty input circuit. Have a technician diagnose the board.
Related error codes
Information compiled from manufacturer service manuals, official troubleshooting documentation, and appliance repair industry resources. This guide is for informational purposes only — always consult a qualified technician for complex repairs.
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