LG Refrigerator Error Code F-SEN

F-SEN indicates that the LG refrigerator's self-diagnostic system has detected a failure in the freezer temperature sensor. The display will blink at the location of the troubled sensor. The fault can be either a short circuit (0 ohms) or an open circuit (infinite ohms), measured at connector CN30 between pins No.3 and No.7. This sensor is critical for regulating freezer temperature, so the issue should be addressed promptly.

Continuing to run the refrigerator with an active F-SEN code is not recommended. Without accurate freezer temperature data, the control board cannot reliably regulate cooling cycles, which may result in the freezer running too warm or not at all. This puts frozen food at risk of spoilage. Addressing the fault as soon as possible is the safest approach.

A power reset may temporarily clear the F-SEN code from the display, but it will return if the underlying sensor fault is still present. The self-diagnostic system will re-detect the failure once the refrigerator restarts its monitoring cycle. A permanent fix requires identifying and correcting the root cause, whether that is a failed thermistor, damaged wiring, or a faulty connection at CN30.

A knowledgeable DIYer can attempt to diagnose the F-SEN code by checking the wiring and connector at CN30 for visible damage, corrosion, or loose pins. Measuring resistance between CN30 No.3 and No.7 with a multimeter will confirm whether the sensor is shorted or open. Replacing the freezer thermistor is a moderately straightforward repair, but if the control board is suspected, professional service is recommended.

If only the freezer thermistor needs replacement, parts and labor costs typically range from around $100 to $250 depending on the specific model and service rates in your area. If the wiring harness requires repair or replacement, costs may be similar or slightly higher. A control board replacement, if needed, is generally the most expensive outcome and can range from $200 to $500 or more.