4 common reasons of sparking inside microwave

Microwave sparking problem

Sparking inside microwave is common and does not indicate that your microwave has gone bad. When a microwave sparks most people panic. But this situation is not to panic. It requires you to immediately switch off your microwave and perform the necessary inspection.

The possible reasons for sparking and arcing inside microwave are:

1. Metal scarp inside microwave

A small metal piece is enough to cause a spark inside your microwave. For example you may have cleaned the microwave with steel wool and left behind some metal scrap from the wool. Also sometime the food which you heat has a foil covering over it that catches fire. If your heating dish is not microwave safe, there are fair chances of sparking. So make sure that there is no metal scrap and your heating dish is microwave safe before you start cooking food in your microwave.

2. Damaged wave guide cover

There is a cover called wave guide cover over the magnetron which conveys or guides the heat waves to the central area where food is kept. Wave guide cover also prevents any food particle or bug from entering the magnetron.

It is very common that during cooking, some food particles and grease escape the food and stick to the wave guide. The heat emitted from the magnetron burns these stuck food particles, which appears as spark to us. This spark damages the wave guide cover. A damaged or shorted wave guide cover causes frequent sparks. So the solution is to remove the burned wave guide cover with a new one.

Recommended wave guide cover for your microwave that you can buy online:

Our Pick

Other recommendations:-

3. Damaged Rack support

Some microwaves have a rack supports, which is a hook like part . If the microwave is sparking near one of the support rack, this means that the paint on the rack has worn out. So remove the support and replace it with a new one.

Our Pick

4. Diode burn

The high voltage diodes could be shorted or burned causing sparking inside microwave.

Our Pick

5. BONUS! – Microwave incompatible cookware can also be a reason for the sparking

There is a possibility that you’re using utensils which are not compatible with your microwave. Thus, following are some utensils suitable for heating food in microwaves that are available on Amazon:

Our Pick

Other Recommendations:-

So next time if you see spark inside your microwave, do not get scared. Immediately switch off the microwave and perform the necessary inspection before calling a technician.

For any kind of microwave repair, hire trusted professionals with Mr. Right

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  1. 1

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  2. 2

    Don’t forget a less obvious reason for sparkling – the food item contains metal fragments.

    We microwave all the time so the sparkling is NOT a microwave issue.

    we put a serving of canned corn (From China) into Microwave and noticed random sparkling and smoke.

    Put bacon into microwave and no sparkling etc.

    Put different serving of canned corn (from same can) and sparkling etc immediately.

    So buyer beware…

  3. 3

    Hi sir I read tips i already done but still getting spark . When i start 30 sec two times no spark and 3rd time i start 1 minute getting spark.
    Can u pls give tips for this problem sir . Thanking you sir

  4. 4

    Terminal s of Magnetron is getting burn & spark is generating when we switching ON. Observed Magnetron 2 terminals are covered with smoked. What is remedying for this problem plz suggest.
    Pavan kumar podishetti
    +91 9948888257

  5. 5

    Terminal s of Magnetron is getting burn & spark is generating when we switching ON. Observed Magnetron 2 terminals are covered with smoked. What is remedying for this problem plz suggest.
    Pavan kumar podishetti

  6. 6

    Just installed a brand new Frigidaire Gallery microwave and I had sparks in it and it burned the side plus the inside of the door has a paint chip caused by the sparks

    I am very upset we bought it 3 months ago and installed it this week since we were redoing our kitchen. Now I am sure home depot will not take it back or should I call the company? I do not want this in my home to be a fire hazard or even a new one from them

    Any thoughts?



  7. 7

    I put a foil inside the microwave then suddenly its. Spark the wide cover has Little bit Burn.. Is there still safe using. Or not .. I’m so scared..

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    After the spark in my microwave, I noticed the side of the microwave next to the wave guide melted into the shape of a crescent. the microwave still works. Should I be concerned? Should I cover hole with something?

  10. 10

    “heat waves”, “heat emitted from the magnetron”. OMG… hashtagflatearth… I think I’m going to look for another page in this topic… I just got braincancer. :-(

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    Because you pointed out that there could be some sparking inside due to a metal scrap, I’ll be sure to check it out if it’s the case with me. I do agree that a damaged waveguide cover can also cause that which I think I’ve removed for a long while now. Since you said that it could be due to damaged rack support as well, we might have the microwave repaired as soon as possible so that the spark will go away.

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    my micro oven starts to spark after we switch on .the technician from the company said the magnetron is damaged so he put a new one but still the sparking continued,

    after a while the technician mention a cavity was burned and that had to be replaced and the total cost would sum upto 6000,we dont know whether to get rid of it or buy a new one
    .please guide us,

  16. 16

    I put a bowl of Ramen Noddles in the microwave for one minute when i usually put it in for five minutes. it exploded my microwave and it set fire to it, taking a full day to air out the house. they noodles were in a microwave safe bowl and i followed the instructions. WHAT HAPPENED?

    • 17

      Tasha Krahn, What kind of cover did you have on your Ramen? If it was not allowed to vent, you superheated the water/broth to the point it developed a gas bubble and burped. Literally the water was well over 212F below the surface (microwaves do not cook evenly) and separated into hydrogen and oxygen, the bubbly rose but found resistance with the noodles and other food or just the top cover, until it exerted more pressure up than the lid was holding it down with and a little water bomb went off. Messy, potential burns form the hot water had you opened the door then, but from an electrical point of view, the microwave operated just like it is supposed to. Nothing wrong with the microwave, just be careful with the food in it and make sure you poke some holes in the wrap or leave one corner loose on the lid.

  17. 18

    microwave is sparking, burned the paint off the wall , i replaced the wave cover, repainted the wall with correct paint, continues to spark, looking into the hole behind the cover there is a cylinder shaped item with burn damage, would love some ideas to fix, please advise

  18. 19

    Thanks so much for info as I was certain I had ruined my new microwave. Wondering what would I do without it so Google Drive this site and found you! Thanks so much, just needed to clean the rack.

  19. 20

    Dear Ms Mishra,

    I just wanted to thank you for this article.
    My microwave begun doing a fairly good impression of a firework and it turns out my wave guide cover was at fault. I’d never have thought so before reading this as it wasn’t even noticeably dirty (save a small scorch mark that must have been food once). I’d switched off and googled immediately bringing me here so a good clean and now it’s a happy hotter again!
    Having worked 18 hours yesterday then a somehow more stressful 11 today with only 4 hours between them, only to then wonder why my microwave was trying to kill me… (you get the picture).
    You’ve made my day =)

    Thanks again,

  20. 22

    Omg. I bought a new microwave and after checking this all I needed was a new wave guide. And two seconds to replace it.Guess what’s getting returned. Thanks for the info.

  21. 23

    So, I pulled the wave guide cover, filed down a “scarp” of metal in the hole cleaned everything. No sparks! However it looked as if it was melting the edges of the hole behind where the wave guide cover was. Is that because the wave diffuser was missing?

    • 24

      I was smelling an odor several times like burnt plastic, then it sparked. Is this a sign it is in need of replacement?

  22. 25

    I actually forget a steel spoon inside the microwave and just switched it on the microwave had a spark inside and i just stopped it now im scared to on it is my microwave in danger or do i have to change it ?

  23. 26

    exactly what you have explained. The guide cover becomes conductor due food particle contamination. Certain portion of it having metal deposition. The magnetron front circular face worn,
    I have cleaned the cover/pa[er and attached, Now no problem. But some portion of the cover worned. What kind of material can be used as cover?

  24. 27

    our microwave sparked in the back where the vent thing is… It happened twice and I think we’re just going to get a new one.. not sure what the cause is. We also have roaches and suspect they screwed something up in the microwave.

  25. 28

    our microwave arced and has a burn mark non outside behind seal the repairman said it was due to food particles and we would have to pay for a new one any thoughts as i think he is an idiot but want to be sure before i go on a rant.

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