Maytag Microwave Error Code F2

The F2 error code on a Maytag microwave indicates that the control board has detected a short circuit condition in the thermistor circuit before a cooking cycle begins. The thermistor is a temperature-sensing resistor that monitors the internal cavity or component temperatures. During the pre-cook self-check, the control board reads the thermistor's resistance value to confirm it falls within the expected operating range. A short circuit condition means the resistance has dropped far below the normal range, essentially reading near zero ohms, which signals to the control board that something is wrong with the sensor or its wiring before any cooking begins.

Thermistor short circuits are typically caused by one of three scenarios: physical damage to the thermistor component itself, a wiring harness fault such as a pinched or chafed wire creating a path to ground, or moisture intrusion that has compromised the sensor or connector. Because the fault is detected before cooking starts, the microwave will refuse to operate as a safety measure, preventing inaccurate temperature monitoring during a cook cycle. The control board cannot distinguish between an actual over-temperature event and a failed sensor if the sensor reads incorrectly.

Diagnosing this fault requires disconnecting the thermistor from the wiring harness and testing the component in isolation with a multimeter. A shorted thermistor will read near zero ohms resistance at room temperature rather than the expected resistance range for the specific sensor. If the thermistor reads correctly when disconnected, the fault lies in the wiring harness or the control board's sensor input circuit itself.