LG Refrigerator Error Code rr

The rr error code on an LG refrigerator indicates that the control board has detected a fault in the R/Room temperature sensor circuit. This sensor monitors the ambient temperature inside the fresh food or room section of the refrigerator, and the error is triggered when the circuit reads either a short circuit (resistance at or near 0 ohms) or an open circuit (resistance at or near infinity). Under normal operating conditions, the sensor should return a finite resistance value that falls within a specific range, allowing the control board to accurately regulate cooling cycles.

The R/Room sensor is a thermistor, meaning its resistance changes predictably with temperature. When the control board cannot read a valid resistance value from this sensor, it cannot determine the correct compartment temperature, which may cause the refrigerator to run inefficiently, overcool, undercool, or stop a cooling cycle entirely. The fault is detected through the wiring harness that connects the sensor to the main control board, so the problem may originate at the sensor itself, the connector, or anywhere along the wiring path.

Diagnosing this error begins with a physical inspection of the sensor connector to confirm it is fully seated and free of corrosion or bent pins. If the connector is secure, resistance should be measured directly across the sensor terminals using a multimeter. A reading of 0 ohms points to a short circuit within the sensor or wiring, while an infinite reading indicates an open circuit, most commonly caused by a broken sensor element or a severed wire. Replacing the faulty component resolves the error once the root cause is confirmed.