KitchenAid Microwave Error Code F3

F3 means the control board has detected a problem with the temperature sensor circuit. Sub-code E0 indicates an open circuit (no continuity through the sensor), while E1 indicates a shorted circuit. Both conditions tell the microwave the sensor is not providing valid resistance readings, so the unit shuts down to prevent unsafe operation.

No. When F3 is active, the microwave will not operate because it cannot monitor cavity temperature. Attempting to bypass or ignore this fault is not advisable, as the temperature sensor is a safety component that prevents overheating. The unit needs a functioning sensor before normal cooking operation can resume.

Unplug the microwave before opening the cabinet. Locate the temperature sensor, typically mounted in the microwave cavity or on the interior wall, and disconnect its wiring connector. Set a multimeter to the ohms setting and place the probes across the two sensor terminals. At room temperature near 70 degrees Fahrenheit, a working sensor reads approximately 1080 ohms. The resistance should increase by roughly 2 ohms for every degree of temperature rise. A reading of zero, infinite resistance, or a value far outside this range confirms the sensor has failed and requires replacement.

Start by unplugging the microwave and inspecting the sensor's wiring connector for looseness or corrosion. Reseat the connector firmly. Then use a multimeter to measure the sensor's resistance across its terminals. At 70 degrees Fahrenheit, a good sensor reads approximately 1080 ohms, adding about 2 ohms per degree above that. If the reading is open, shorted, or wildly out of range, replace the temperature sensor. If resistance is correct after reseating the connector, the harness wiring may need further inspection.

If the fix is simply reseating a loose connector, the repair costs nothing beyond your time. A replacement temperature sensor typically costs between $15 and $40 for the part depending on the specific model. If you hire a technician, expect a service call fee plus labor, which can bring the total to $100 to $200. Given that sensor replacement is a low-complexity repair involving basic multimeter work and a connector swap, many homeowners complete it themselves after confirming the part number for their model.