Whirlpool Microwave Error Code F3.T2

The F3.T2 error code on a Whirlpool microwave indicates a failure in the FC (forced convection) thermistor circuit. The forced convection system uses a fan to circulate hot air during convection cooking modes, and the thermistor is the temperature-sensing component that monitors air temperature within that system. When the control board cannot read a valid signal from the FC thermistor, it triggers this fault code to prevent unsafe operation.

The thermistor itself is a resistive temperature sensor whose resistance value changes predictably with temperature. If the control board receives a reading that falls outside the expected resistance range, either too high or too low, it interprets this as a sensor failure and displays F3.T2. The root cause is most often a loose or corroded connector at the thermistor harness, a broken wire in the sensor circuit, or a thermistor that has failed internally and no longer provides accurate resistance output.

Diagnosis begins with disconnecting power to the unit before inspecting the FC thermistor wiring harness for damage, corrosion, or loose connections. If the connector is secure and the wiring is intact, the thermistor itself should be tested with a multimeter to confirm it is producing a resistance reading within the acceptable range for the ambient temperature. A thermistor reading open (infinite resistance) or shorted (near zero resistance) confirms component failure and replacement is required.