If your microwave fan turns on when the door opens, you likely worry about an inherent safety issue. However, a faulty switch in the door frequently causes this problem. This switch tells when the door is opened or closed, turning on and off the best microwave.
To avoid these interlock issues, you may want to check or replace your door switch as described below. If this process does not help, you may need to reach out to your repair service. You may also be interested to know how to replace a microwave turntable motor for future fixes.
Unplug the microwave before starting to protect yourself from electrocution or shock.
The primary issue that could affect when the fan turns on or off comes from the interlock switch. If this feature isn’t working right, the microwave doesn’t know that the door has been opened or closed. You should try resetting the power at the circuit breaker first to get a better idea of the issue. Unfortunately, this issue is relatively common and can result from a faulty switch or a sticky switch.
On the other hand, if it’s from a delayed switch, your microwave will eventually react to the door being open. Therefore, you may also want to know how to replace a microwave door.
You probably will need multiple screwdriver heads, so you should check if anyone in your house has a screwdriver with replaceable bits.
Why does my microwave fan turn on when I open the door?
If your fan turns on when you open the door, your door switch may be stuck or not working. However, sometimes other issues cause this problem, so it may take longer to troubleshoot.
What do you do if your microwave fan won’t turn off?
Keep the door closed when you aren’t using it. If you want to try fixing the door switch, you can find the instructions above. However, you may end up calling a service shop.
Will operating a microwave oven while empty damage the equipment?
You should never run a microwave without anything inside, because doing so may damage the microwave and cause issues during use.
STAT: If the door continues to run even when you open the door, then it is likely a door interlock switch fault. (source)