Kenmore Refrigerator Error Code Er rt

Er rt indicates a room temperature sensor error. The control board has detected either a short circuit or a disconnection in the room temperature sensor circuit and is no longer receiving a valid signal from it. This sensor monitors the ambient temperature surrounding the refrigerator to help regulate cooling performance.

The refrigerator will likely continue to run and maintain cooling with Er rt active, but it is operating without accurate ambient temperature data, which can cause it to cool inefficiently or behave erratically in extreme room temperatures. It is safe to use temporarily to preserve food, but the underlying sensor fault should be diagnosed and repaired promptly to avoid long-term performance issues.

Disconnect the room temperature sensor from the wiring harness and use a multimeter set to measure resistance (ohms). At typical room temperature, around 77°F or 25°C, most refrigerator thermistors read in the range of 5,000 to 10,000 ohms, but confirm the exact spec for your model in the service manual. A reading near zero ohms indicates a short; a reading of infinite resistance (OL) indicates an open. Either result means the sensor needs to be replaced.

Start by unplugging the refrigerator and locating the room temperature sensor, then check that its connector is fully seated and free of corrosion. If the connector is secure, use a multimeter to measure the sensor's resistance and compare it against the spec in your service manual. A shorted or open reading confirms a failed sensor that needs to be replaced. If the sensor tests good, inspect the entire wiring harness between the sensor and the control board for damage before considering a board replacement.

If the fix is simply reseating a loose connector, there is no parts cost. A replacement room temperature sensor typically costs between $10 and $40 depending on the specific Kenmore model. If the main control board turns out to be the cause, board replacement can run $100 to $300 or more for parts alone. A technician visit adds a diagnostic fee and labor, commonly $75 to $150 per hour, so attempting the connector and sensor checks yourself first is a reasonable approach before calling for service.