GE Range Error Code F100

The F100 error code on a GE range indicates that the NTC (negative temperature coefficient) sensor mounted on the magnetron case has detected a temperature reading that exceeds the allowable upper limit. The NTC sensor is a thermistor-based component whose electrical resistance decreases as temperature increases. When the control board reads resistance values that correspond to an over-temperature condition at the magnetron housing, it triggers the F100 fault and shuts down microwave operation to prevent damage to the magnetron and surrounding components.

The magnetron is the high-voltage component responsible for generating the microwave energy that heats food. During normal operation, the magnetron produces significant heat, which is managed by a cooling fan and proper airflow through the unit. If the cooling system is compromised, if the unit is run for extended periods without adequate ventilation, or if the NTC sensor itself has failed, the control board may register a temperature beyond the design limit and display F100.

Common contributors to this fault include blocked ventilation paths, a failed or weak cooling fan, and extended cooking cycles that push the magnetron beyond its thermal limits. In some cases the NTC sensor itself can develop a fault, sending an inaccurate signal to the control board that mimics an over-temperature condition even when the magnetron is running at normal temperatures. Accurate diagnosis requires distinguishing between a genuine thermal event and a sensor or wiring failure.