Wolf MWC24 Fire Sensing Shutdown: Rapid Thermistor Voltage Jump

What Fire sensing shutdown means

On Wolf MWC24 and MC24 convection microwaves, the fire sensing shutdown is a safety stop. The control watches a thermistor, and a voltage jump of 300 mV within 32 seconds from its base reading shuts the relays off and closes the damper. You see the microwave stop mid-cycle and stay off, which can follow a heavy flare-up or a sensor misreading.

Common causes of Fire sensing shutdown

Real flare-up or smoke inside the cavity
Thermistor reading that jumped too fast
Damper or vent area holding heat
Control board reacting to the thermistor signal

✓ One safe check you can try

1. If you see flames or smoke, keep the door closed, switch off power at the breaker, and call 911 if needed. 2. Once cool, open the door and remove food and any residue. 3. Wipe the cavity and wait until fully cool. 4. Reset the breaker. If the shutdown repeats with a clean cavity, call us.

! Why to stop there

This is a safety lockout, so repeated restarts are not wise.
The thermistor, relays and damper are inside the unit near high voltage.
We find out whether it was a true overheating event or a bad sensor reading.
Our labor is warranted for 30 days.

Opening a panel yourself does not automatically cancel a manufacturer warranty, but it can cause accidental damage, and some manufacturers set their own service conditions. Check your warranty terms, or ask us, before deciding.

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Fire sensing shutdownFire sensing shutdown questions

Why did my MWC24 stop suddenly?

The fire sensing system saw the thermistor voltage jump by 300 mV within 32 seconds. It then turned the relays off and closed the damper to protect you and the oven.

Was there really a fire?

Not always. Heavy splatter, a flare-up or a sensor misreading can all trigger it. If you saw flames or smoke, treat it as real and call emergency services first.

Should I try the microwave again?

Only after it has cooled and you have cleaned the cavity. If the shutdown repeats, stop using it and call us for an inspection. We treat Fire sensing shutdown as the first lead, so you only pay for what is needed.