LG Refrigerator Error Code R-defrost sensor open

This error means the defrost sensor located in the refrigerator compartment, near the evaporator coil, has an open circuit. The control board interprets the sensor reading as below -50°C, which indicates the sensor is not sending a valid signal. The fault affects the automatic defrost cycle, which relies on this sensor to know when the evaporator coil has been fully defrosted. Diagnosis involves checking the sensor's resistance and inspecting its wiring.

Short-term use may be possible, but operating the refrigerator with a non-functional defrost sensor is not recommended for extended periods. Without a working sensor, the defrost cycle cannot terminate properly, which can allow ice to accumulate on the evaporator coil. This ice buildup will eventually restrict airflow, reduce cooling performance, and could lead to food spoilage or additional component damage.

Repair costs vary depending on whether it is a DIY repair or a professional service call. A replacement defrost sensor part typically falls in the range of $15 to $50. If a technician is hired, total costs including labor can range from $100 to $250 depending on your location and the extent of any wiring repairs needed. If the main control board is ultimately found to be at fault, parts and labor costs will be higher.

A knowledgeable DIYer can diagnose this fault by unplugging the refrigerator, locating the defrost sensor near the evaporator coil, and measuring its resistance with a multimeter. If the sensor reads open or infinite resistance, it needs to be replaced. Wiring connectors should also be inspected and cleaned if corrosion is present. If the sensor and wiring appear fine, further diagnosis of the control board is best left to a technician.

A reset may temporarily clear the fault code from the display, but the error will return if the underlying problem with the sensor or its wiring has not been resolved. The control board will continue to detect the open circuit condition every time it checks the sensor input. A permanent fix requires repairing or replacing the faulty sensor or wiring.