LG Refrigerator Error Code RT sensor

The RT sensor error means the control board has detected an abnormal condition in the ambient room temperature sensor circuit, specifically a short circuit or open circuit. This sensor is a thermistor that measures the temperature of the air surrounding the refrigerator so the control board can optimize cooling performance. When the sensor circuit fails, the board can no longer receive a valid temperature reading from it. The error code alerts you that the sensor or its wiring needs to be inspected and tested.

The refrigerator may continue to run with this error active, but without accurate ambient temperature data the control board cannot optimize its cooling cycles properly. This could lead to reduced efficiency or inconsistent temperature performance over time. It is best to address the fault promptly to avoid potential food safety issues caused by improper cooling.

Performing a power reset by unplugging the refrigerator for a few minutes may temporarily clear the error code, but the fault will return if the underlying problem with the sensor or wiring has not been corrected. A reset should not be used as a substitute for proper diagnosis. The error will persist or reappear until the short circuit or open circuit condition in the RT sensor circuit is actually repaired.

A knowledgeable DIYer can perform the initial diagnostic steps, which include checking the connector at CON5 for a loose connection and measuring resistance across the white sensor wires with a multimeter. If the connector simply needs to be reseated, no parts are required. Replacing a failed thermistor sensor is also a manageable repair for someone comfortable working with appliance wiring, though it does require sourcing the correct replacement sensor for your specific LG model.

If the fix is simply reseating a loose connector at CON5, there may be no parts cost at all, though a service call fee from a technician would still apply if you hire one. Replacing a faulty room temperature thermistor sensor typically costs between $20 and $75 for the part alone, depending on the model. With professional labor, the total repair cost generally falls in the range of $100 to $250.