LG Refrigerator Error Code Er (outside sensor)

The Er code on an LG refrigerator indicates that the outside temperature sensor has either an open circuit (broken wire or failed thermistor) or a short circuit. It appears specifically on the outside temperature display while all other displays and refrigerator functions continue to work normally. The control board detected an out-of-range resistance reading from the sensor circuit and triggered the error to alert you to the fault.

This error is isolated to the outside temperature sensor and does not affect the refrigerator's cooling system or interior temperature control. Your food is not at risk as a result of this specific code. However, you should still address the fault to restore full monitoring functionality and prevent any underlying wiring issue from potentially affecting other components over time.

If the repair is limited to the thermistor sensor itself, parts typically range from around $15 to $50 depending on the model. If professional labor is involved, total repair costs generally fall in the range of $100 to $250 including the service call and parts. Costs can be higher if the wiring harness requires replacement or if the fault is traced to the control board.

A knowledgeable DIYer can start by checking the sensor's wiring connector for corrosion or looseness and reseating it, which costs nothing. If that does not resolve the issue, the next step is measuring the sensor's resistance with a multimeter to confirm whether the sensor itself has failed. Replacing a thermistor sensor is a straightforward repair, but you should be comfortable working with appliance wiring and sourcing the correct replacement part for your specific LG model.

A power reset may temporarily clear the error display, but the code will return if the underlying sensor fault is still present. The control board will re-detect the open or short circuit in the sensor the next time it runs a diagnostic check. A permanent fix requires repairing or replacing the faulty sensor or wiring rather than simply resetting the unit.