LG Refrigerator Error Er rt — What It Means & How to Fix It

What Does This Error Mean?

Er rt means the room temperature sensor — also called the ambient temperature sensor — has a fault. This sensor measures the temperature of the air in your kitchen around the refrigerator. Your LG refrigerator uses this reading to adjust its cooling performance for the current room conditions. When the sensor fails, the refrigerator loses this environmental data. Cooling continues, but efficiency may be slightly reduced in extreme temperatures.

Affected Models

LRMVS3006S
LFXS26973S
LRFXS2503S
LRMDC2306S
LSXS26366S
Most LG French door and side-by-side models

Common Causes

The ambient temperature sensor has failed due to age or environmental exposure
Dust or debris has accumulated on the sensor, insulating it and causing incorrect temperature readings
The sensor wiring connector has come loose at the back of the refrigerator cabinet
The sensor has been exposed to unusual temperatures — very hot or cold garage conditions — outside its range
The main control board has a fault affecting its ability to process the ambient sensor signal

How to Fix It

Unplug the refrigerator for 5 minutes and plug it back in. A power cycle clears temporary sensor faults caused by voltage fluctuations or transient errors.

If Er rt clears after the power cycle and does not return within a few days, it was a temporary glitch. Monitor the error for a week before arranging service.
Check the room temperature around the refrigerator. If the kitchen is unusually hot (above 95°F) or cold (below 50°F), the sensor may be reading out of its designed range.

LG refrigerators are designed to operate in rooms between 55°F and 110°F. In extreme conditions — like an unconditioned garage in summer or winter — the ambient sensor may trigger Er rt.
Locate the ambient temperature sensor — it is usually mounted on the external back or side of the refrigerator cabinet, near the compressor area. Check that the connector is secure.

The sensor is a small probe with a wire leading to a connector. Gently press the connector to ensure it is firmly seated. Loose connectors from vibration are a common cause of Er rt.
Check the area around the sensor for dust buildup. Use a dry cloth or soft brush to clean around the sensor probe. Dust acts as insulation and can cause the sensor to misread room temperature.

This is especially relevant if the refrigerator is in a workshop or laundry room where dust accumulates. A buildup of lint or dust on the sensor can shift its readings.
If Er rt persists after these checks, schedule a service call. Provide the Er rt code when booking. A technician will test the sensor's resistance and replace it if it is out of specification.

Ambient sensors for LG refrigerators cost $15 to $40. The repair takes about 30 to 45 minutes. Check your warranty status first at lg.com/us/support.

When to Call a Professional

Er rt is a moderate repair that does not require emergency service. Your refrigerator will continue cooling while Er rt is active. Ambient sensor replacement typically costs $80 to $180 including parts and labor. Contact LG support at 1-800-243-0000 to check warranty coverage before arranging repairs. This repair can be scheduled at your convenience.

Frequently Asked Questions

Does Er rt affect my refrigerator's cooling?

In most cases, cooling continues normally with Er rt active. The refrigerator switches to a default cooling mode that does not rely on ambient temperature data. This is slightly less efficient than normal adaptive cooling. In extreme room temperatures — very hot or very cold — performance may be more noticeably affected. Get the sensor replaced to restore fully optimized operation.

My refrigerator is in a garage. Could that cause Er rt?

Yes — garages frequently experience temperature extremes outside the operating range for LG refrigerators. In summer, an unconditioned garage can reach 110°F to 130°F — beyond the sensor's rated range. In winter, temperatures below 50°F can also push the sensor out of its valid range. LG sells a separate Garage Kit for models that support it, which adjusts the refrigerator's operation for garage environments. Check your model's compatibility at lg.com/us/support.

Is the ambient sensor the same as the internal temperature sensor?

No — they are separate sensors measuring different things. The ambient (room temperature) sensor measures the temperature outside the refrigerator in the kitchen or room. The internal sensors — fridge sensor (Er RS) and freezer sensor (Er FS) — measure temperatures inside the compartments. Each has its own error code. Er rt specifically refers to the external ambient sensor, not the internal ones.