White Smoke From Microwave (Causes And How To Fix)

By Nick Evans •  Last Updated: 05/21/21 •  6 min read

Do you have white smoke coming from your microwave? Wondering what to do about it? You’re in the right place.

In this article, we break down exactly what causes a microwave to smoke, as well as how to fix it.

Keep reading to learn:

  • Why is my microwave smoking?
  • Is smoke from a microwave dangerous?
  • What to do if your microwave is smoking?
  • How to fix a microwave that is smoking?
white smoke from microwave

As of 2020, some 80 to 90 percent of households now own microwaves, according to Statista. As the rate of microwave ownership has increased, so have the number of problems associated with using them.

If your microwave is currently smoking, unplug it immediately, and if possible, open your windows and doors.

If you fear for your safety, call 911 right away.

Why is my microwave smoking?

There are many reasons as to why smoke could be coming from your microwave. Some are more serious than others, but anytime you have a smoking microwave, safety should be the top priority.

First and foremost, make sure you unplug the microwave. If the smoke is bad enough, open your windows and doors. If there is a fire, call for emergency help, or use a fire extinguisher.

With that note, let’s explore some of the common causes that can cause smoke in a microwave.

Microwaving your food too long

It can be easy to press the wrong button on your microwave. This could lead to accidentally cooking your food for ten minutes instead of one. With that, there is a chance that the prolonged heat could cause your food to smoke and ultimately, catch fire.

Thankfully, this means that there’s nothing wrong with the microwave itself. In this instance, if you catch the situation early enough, all you need to do is clean up the microwave. We recommend using a good sponge and if needed adding in some detergent. 

Electrical issue inside the microwave

If you have an electric problem inside your microwave, it could be the diode inside your microwave has shorted. When diodes open or short, they have a tendency to spark. This could be the source of your smoke.

It is important to tread carefully when disassembling your microwave. You want to decrease the risk of electrocution. If you are inexperienced or feel unsure, we recommend contacting a licensed electrician.

When various electrical components fail, they usually produce an unpleasant scent that can linger for many weeks afterwards. Without proper ventilation, they can become overbearing, and in some cases, toxic. 

Metal in your microwave

It’s likely that at some point either you or someone you know has accidentally microwaved something metal.

Because microwaves reflect off of metal instead versus the waves actually passing through as they do with plastics, ceramics, and most types of food, putting metal inside a microwave will cause arcing (meaning sparks will fly off, possibly starting a fire).

When in doubt, err on the side of caution. As a general rule, it’s best to steer clear from putting anything made of metal inside of the microwave.

Recommended >> 5 best countertop microwaves

Cooking food that isn’t supposed to be microwaved

Some food simply isn’t meant to be placed inside the microwave.

When put in a microwave, foods such as grapes and nuts can catch fire or begin to smoke due to their low water content and chemical composition.

If you have a question about whether you should microwave a certain food, consult Google.  

Is the smoke from a microwave dangerous?

Yes, in most instances, smoke from a microwave is a safety hazard.

Water vapor is about the only type of smoke-like substance from a microwave isn’t dangerous. The vapor is easy to identify as the “smoke” will smell like water and dissipate quickly.

However, if your microwave is smoking, and the scent is unpleasant, or smells different from the food you are cooking, this may be harmful.

If you are microwaving plastics and see smoke, this is likely cause for alarm as the smoke might contain dioxins and dibenzofurans, which can be hazardous to your health.

Regardless of the reason your microwave is smoking, the most important consideration is your safety. If you suspect the smoke is anything other than water vapor, act immediately to unplug your microwave and ventilate your home.

What to do if your microwave is smoking?

white smoke from microwave

Once you have identified the cause of the smoke from your microwave, it’s time to fix it.

First, unplug your microwave. Then, transport it outside to let it air out. If the fumes are strong or you’re unable to pick up the microwave without inhaling the smoke, open all the windows in your house, and let the smoke dissipate. 

Once all the smoke has disappeared, inspect the waveguide cover. This is a tiny panel on one of the microwave’s thicker sides. If it seems to be damaged, you can order a new one and install it yourself.

In certain cases, you may be better off simply replacing your microwave.

Before purchasing a new microwave, make sure to check your warranty if you have one. You may be able to get a replacement part or even a new microwave.

How to fix a microwave that is smoking

If your microwave is not smoking due to an electrical problem, you can more than likely resolve the problem yourself.

A deep clean can go a long way.

Firstly, clear off any residue left by food that may have splattered in the microwave. This will remove the chance of small crumbs or food residue being the source of a potential smoke out. 

Next, check your microwave’s wave guide cover. As stated above, if this is damaged, consider ordering a new one.

If the above suggestions do not solve the issue, it may be time to consult a handyman or electrician. 


White smoke from your microwave is alarming. Above all, prioritize the safety of yourself and your family. Once you have done that and feel you’re in a comfortable place to inspect the cause of the smoke, jot down some notes as to your findings. If you end up needing the help of a professional, these will come in handy.

I hope this guide was helpful!

If you have any questions or comments, please feel free to contact us or comment below.

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