Microwave displays F3 and may stop cooking; sometimes occurs during long cook cycles.

Safety first: Unplug the microwave or turn off the breaker. Microwaves contain high-voltage components; do not access the magnetron or capacitor area.

Basic reset:

• Disconnect power for 5–10 minutes to clear the code. If F3 returns quickly, proceed with sensor checks.

Locate and inspect sensor:

• On many Maytag over-the-range models, the cavity temperature sensor (thermistor) is mounted inside the oven cavity wall or on the top/side behind the inner liner.
• Remove the top grille and control panel to access the wiring harness. Look for a small two-wire sensor harness labeled with temperature or sensor markings.
• Check for loose connectors, burnt spots, or damaged insulation. Reseat any loose plugs.

Test the sensor (for experienced DIYers with a multimeter):

• With power still disconnected, unplug the sensor from the harness.
• Measure resistance across the sensor terminals. Compare to service documentation (commonly 50–300 kΩ at room temperature depending on design). A reading of 0 Ω (short) or infinite (open) indicates a bad sensor.

Corrective action:

• If the sensor is out of spec or physically damaged, replace the cavity temperature sensor / thermistor.
• If the sensor tests good but F3 persists, the electronic control board may be defective and require replacement.

Warning: If you are unsure of sensor location or readings, consult a service manual or technician. Do not operate the microwave with panels removed.