LG Refrigerator Error Code F-defrost sensor short

This error means the freezer compartment defrost sensor has a short circuit fault. The control board is detecting a sensor reading that corresponds to a temperature above +50°C, which indicates the sensor or its wiring circuit is not functioning correctly. The defrost sensor is a thermistor located near the evaporator coil, and a short circuit prevents it from accurately reporting evaporator temperature during the defrost cycle.

The refrigerator may continue cooling in the short term, but the defrost cycle could be compromised, leading to progressive frost buildup on the evaporator coil. Over time, this frost accumulation will restrict airflow and degrade cooling performance in both the freezer and fresh food compartments. It is best to address the fault promptly to prevent secondary damage.

A power reset may temporarily clear the error code from the display, but the fault will return if the underlying problem with the sensor or wiring has not been resolved. Resetting the unit does not repair a shorted sensor or damaged wiring. A proper repair requires diagnosing and replacing the faulty component before the error will stay cleared.

A knowledgeable DIYer can diagnose this error by checking the defrost sensor resistance with a multimeter and visually inspecting the wiring harness for damage or corrosion. If the sensor resistance is out of specification, replacing the sensor is a straightforward repair involving the freezer back panel. However, if the fault traces back to the main control board, that repair is more complex and may warrant professional service.

If only the defrost sensor needs replacement, parts typically cost in the range of $15 to $50 depending on the specific model, making it one of the more affordable refrigerator repairs. Professional labor to diagnose and replace the sensor generally adds $80 to $150 to the total. If the main control board is at fault, parts alone can range from $100 to $300 or more.