I put two small purple sweet potatoes in the microwave for 12 minutes and they burned in my new microwave. My dad claims I destroyed the microwave because I burned something in it just once. Is he right!? If that were the case, I’d think most people would be buying new microwaves every month and that’s not the case.

If the microwave still works, when can I use it again?

  • 1
    Why exactly does he claim that it is broken?
    – Summer
    Commented Mar 2, 2019 at 2:10
  • Because I broke the last microwave I had but that one was a decade old. I don’t think he knows what he’s talking about. He always errs on the side of caution.
    – brown1001
    Commented Mar 2, 2019 at 2:11
  • 6
    I have no idea why he would think a single burnt potato broke your microwave. I would need more detail as to why he believes that to refute it properly but it is rather absurd. That's not the side of caution, that is alarmist catastrophizing.
    – Summer
    Commented Mar 2, 2019 at 2:14
  • 1
    The only thing I can think of is that it can be hard to get the burnt smell out of the microwave. If you manage that it is certainly fine to use.
    – user141592
    Commented Mar 2, 2019 at 14:39
  • I'm going to second the issue with the burning smell. I once set some potatoes on fire in a microwave (so well that one vaporized, and other was glowing from the middle of it), and it had that burning hair smell for months afterwards.
    – Joe
    Commented Oct 28, 2020 at 1:05

2 Answers 2


I think most people don't realize a microwave oven is just a radio transmitter. The cavity you put your food into is part of a tuned area for this transmitter. Instead of feeding the output of this transmitter into an antenna, the power is contained within the cavity and, thus, warming the food. Note: extremely simplified statements.

Mistuned transmitters can cause a mismatch with their antenna. The same thing happens when there is little to no food inside the microwave cavity. Such issues can cause the magnetron, the microwave's "tube", to overheat and cause damage to itself. However, by not being a solid state device, and by being more of a mechanical device, it can withstand mismatches and overheating for a more extended period of time whereas, a semiconductor device (transistors and integrated circuits), could fail within seconds.

This is why manufacturers warn not to run the microwave without anything in the oven. But you did not do that. For most of the 12 minutes, you had potatoes in there. The quality of this "load" on the microwave element deteriorated over time but it wasn't zero. If you had left it like that for half an hour or more, I could claim there would be a deterioration of the magnetron tubes "quality" but it is not anything I would concern myself with and I don't think it would even be measurable.

Source: me. Electronic engineer but haven't dealt with transmitters in a long time.


As long as you clean the insides, you should be fine to use it again whenever you want.

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