Er rt Moderate Moderate DIY

LG Refrigerator Er rt — Room (ambient) temperature sensor fault

LG Refrigerator · Error code Er rt

What Er rt Means

The external ambient temperature sensor is open, shorted, or disconnected. The board uses this for anti-sweat / condensation heater logic and may default to a fixed value.

Symptoms

  • Er rt on display
  • Anti-sweat heater always on (cabinet exterior warm)
  • Condensation issues around door frame
  • Cooling continues normally

Common Causes

1
Disconnected ambient sensor

Plug unseated, especially after rear panel service.

2
Failed thermistor

Sensor element failed open or short.

3
Main board input failure

Rare ADC fault.

How to Fix It

  1. Unplug for 5 minutes to attempt soft reset.
  2. If error returns, remove the rear access panel to locate the ambient sensor (usually mounted near the machine compartment).
  3. Reseat its connector.
  4. Ohm the sensor at room temp against LG spec.
  5. Replace sensor if out of spec.
  6. If still active, replace the main control board.

Parts You May Need

If diagnosis points to a failed part, these are the common replacements. As an Amazon Associate we earn from qualifying purchases.

Common replacement Ambient/room temp sensor View on Amazon→

More LG Refrigerator Codes

22 22 — Compressor relay / inverter control fault 33 33 — Compressor / defrost test fault 67 67 — Door open / not fully closed 88 88 — Power-on display test (not a fault) Er CF Er CF — Condenser Fan Fault Er CO Er CO — Compressor / Communication Fault

All LG codes → All refrigerator codes →

Verified against manufacturer documentation: lg.com

Always unplug an appliance before servicing it. This guide is for informational purposes and is not a substitute for a qualified technician.