Kenmore Refrigerator Error Code Er FS

Er FS means the control board detected a short or disconnection in the freezer temperature sensor circuit. The board can no longer get a valid temperature reading from the freezer sensor, so it throws this code to alert you to the fault. The issue is somewhere along the Blue/White to Blue/White sensor wiring or in the sensor itself.

Continued use carries real risk to frozen food. With the freezer sensor circuit open or shorted, the control board cannot accurately monitor freezer temperature, meaning the compressor may underrun or overrun. Food in the freezer may not stay at a safe temperature. Running the unit briefly while you source parts is generally acceptable, but monitor internal temperatures with a standalone thermometer and do not leave the unit unattended for extended periods with perishable food inside.

Unplug the refrigerator, then locate the Blue/White wire connector for the freezer sensor. Disconnect it and set a multimeter to the ohms setting. Place the probes on the two sensor terminals and read the resistance. The exact expected value depends on the current temperature inside the freezer, but a functioning NTC thermistor sensor will show a measurable resistance in the thousands of ohms at freezer temperatures. A reading of zero ohms or OL (open loop) confirms a failed sensor or broken wire, and the faulty component should be replaced before running the refrigerator again.

Start by unplugging the refrigerator and locating the freezer sensor connector on the Blue/White wires. Disconnect and firmly reseat it, then restore power to see if the code clears. If it returns, use a multimeter to measure resistance across the Blue/White wires at the sensor connector. A working sensor will show a resistance value consistent with the ambient freezer temperature, typically several thousand ohms near 0 degrees F. A reading of zero ohms indicates a short; an open line with no continuity indicates a broken wire or failed sensor, either of which requires part replacement.

A replacement freezer temperature sensor typically costs between $15 and $40 for parts. If you are comfortable using a multimeter and accessing the sensor location inside the freezer compartment, this is a DIY-level repair for most people. A service call from a technician will add $80 to $150 or more in labor depending on your area. Replacing the control board, if that turns out to be the cause, costs significantly more in parts, often $100 to $250, making the sensor and wiring the much more cost-effective diagnosis to rule out first.