LG Refrigerator Error Code F-defroster sensor open

This error means the freezer area defrost sensor has an open circuit fault. The control board is receiving a temperature reading below -50°C, which indicates the sensor is no longer sending a valid signal. The defrost sensor is a thermistor that monitors freezer temperatures during the defrost cycle, and an open circuit means that electrical path has been broken. The issue typically points to a failed sensor, damaged wiring, or a loose connector.

The refrigerator may continue cooling in the short term, but the defrost cycle cannot operate correctly without a functioning defroster sensor. Over time this leads to frost buildup on the evaporator coils, which reduces airflow and cooling efficiency. It is best to address this error promptly to avoid food spoilage or further component damage.

A power reset may temporarily clear the error code from the display, but the fault will return if the underlying problem has not been resolved. Because the error is triggered by a hardware condition, specifically an open circuit in the sensor, the code will reappear as soon as the control board performs its next sensor check. Proper repair requires inspecting and, if necessary, replacing the defective sensor or wiring.

Start by running the refrigerator's built-in self-test or diagnostic mode to confirm the fault is isolated to the F-area defroster sensor. Inspect the wiring harness and connector between the sensor and the control board for breaks, corrosion, or loose terminals. If the wiring checks out and the fault persists, replace the freezer defroster sensor. A qualified technician can complete this repair if you are not comfortable working with appliance wiring.

If only the defroster sensor needs replacement, parts typically range from $15 to $50 depending on the model, and professional labor can add $80 to $200 depending on your location and the technician's rate. If the issue turns out to be a damaged wiring harness or connector, repair costs may vary. Getting a diagnostic visit from a certified technician will give you a more accurate estimate for your specific unit.