Maytag Microwave Error Code F3

The F3 code on a Maytag microwave means the control board has detected a short circuit in the thermistor, which is the component that monitors internal cooking cavity temperature. The fault is triggered after a cooking cycle when the control checks the thermistor's resistance reading. This indicates the thermistor, its wiring, or the control board input circuit requires inspection and likely repair before the appliance should be used again.

Continued use of the microwave while the F3 code is active is not recommended. The thermistor is a safety-related component that helps the control board monitor temperature and prevent overheating. Operating the appliance without a functioning thermistor circuit means the microwave cannot properly detect abnormal temperature conditions during cooking.

Unplugging the microwave for a few minutes and restoring power may temporarily clear the F3 code, but the fault will return if the underlying problem with the thermistor or its wiring has not been corrected. Because the fault is detected after cooking, it will typically reappear the next time you run a cooking cycle. A reset alone is not a repair and the root cause should be diagnosed and addressed.

A technically experienced DIYer may be able to diagnose and resolve the F3 code by testing the thermistor resistance with a multimeter and inspecting the wiring harness for damage or corrosion. Replacing a thermistor is generally straightforward if the component is accessible and a compatible replacement part is available. However, microwave repair involves capacitors that can store lethal voltage even when the unit is unplugged, so internal work should only be performed by those familiar with high-voltage appliance safety procedures.

Repair costs depend on which component has failed. Thermistor replacement parts typically range from around $10 to $40, while a new control board can range from $80 to $200 or more depending on the model. If you hire a professional appliance technician, expect to add labor costs of roughly $75 to $150 on top of parts, though total costs vary by region and service provider.