Microwave Smells Like Burning Plastic? Fix It in 6 Easy Steps

It’s happened to many of us: you open the microwave and smell burning plastic. That scary smell can make you worry—did you melt something? One time, I heated a plastic bowl that wasn’t microwave-safe, and that awful smell filled the kitchen. In this post, I’ll explain why this happens and how you can stop it for good!

Check If It’s Just New

When I bought my new microwave, I was super happy. But then, the first time I used it, I smelled something strange — like burning plastic. I got really scared and thought it was broken. But later, I found out that many new microwaves smell like this when used for the first time. It’s actually normal in most cases.

This happens because new microwaves have parts like plastic covers, paint, and wires that heat up for the first time. These parts are still fresh from the factory. When they get hot, the smell of plastic can come out. It usually goes away after a few uses.

But how can you know if it’s just that new smell or something serious? Here’s what I did. I ran the microwave empty for 3 minutes with a cup of water inside (never run it totally empty!). The smell was still there the first time. But after using it 3 or 4 times, the smell was gone.

You can also read the manual. Some companies even mention this smell in the manual and say it will go away. If your microwave is brand new, and there is no smoke or loud sounds, the smell might be normal. But if the smell gets worse, or smoke starts to come out, stop using it immediately.

Always be careful. Even if it’s new, a strong burning smell should not last more than a few uses. If it keeps happening, then it’s not just a new smell.

• New microwaves can smell like burning plastic.
• It happens due to heating of factory materials.
• Smell should go away after a few uses.
• Run it with water for short times.
• Stop using it if smell gets stronger or smoke appears.

Look Inside for Melted Items

One day, I put some food in a plastic container inside my microwave. I didn’t think much about it. But soon, I smelled something burning again. This time it wasn’t just a little smell. It was strong, and when I opened the door, I saw the plastic container had melted a little on the side.

Microwaves heat things very fast. Some plastic containers are not made for that kind of heat. When you use the wrong plastic, it can melt, burn, or even catch fire. That’s very dangerous. The smell that comes from melted plastic is sharp and stays in the microwave for a long time.

Always check if the container is microwave-safe. It usually says “microwave safe” on the bottom of the container. If you are not sure, don’t use it. Glass or ceramic is much safer to use.

Also, check under the glass plate inside the microwave. Sometimes food or plastic wraps can fall and melt there. These melted parts keep heating again every time you use the microwave, and that can create a burning smell.

If you find melted plastic or food stuck inside, clean it right away. Unplug the microwave first. Use baking soda and warm water to scrub gently. Never use strong chemicals inside the microwave.

If the smell remains even after cleaning, leave the microwave door open overnight. Put a bowl of baking soda inside to absorb the smell. This helps a lot.

• Melted plastic or wraps can cause burning smells.
• Always use microwave-safe containers.
• Check inside carefully for melted parts.
• Clean with baking soda and warm water.
• Use baking soda to remove the leftover smell.

Check the Microwave Turntable and Wheels

Sometimes, the smell is not from plastic containers or the microwave itself. It can be from the turntable or its wheels. I found this out the hard way. One time, I noticed the glass turntable was not turning smoothly. When I checked underneath, a small piece of plastic from old food had melted on the wheel.

The turntable in a microwave sits on small plastic wheels. These can wear out or get dirty over time. If something sticky or plastic melts there, it will burn each time you use the microwave. And that burning plastic smell will keep coming back.

Take the turntable out and check the ring with wheels. Clean it well. Use a small brush or toothbrush if needed. If any of the wheels look damaged or melted, you can replace the ring easily. You can buy new ones online or from the store where you bought your microwave.

Also, check for small food crumbs under the turntable. Sometimes cheese or plastic wrap can drop down there and melt. Always clean your microwave inside weekly to avoid this.

If the wheel ring is broken or warped, it won’t spin right. That can cause the microwave to heat unevenly and damage plastic containers. This will lead to more smells.

• Burning smells can come from the turntable wheels.
• Clean the wheel ring and under the glass plate.
• Replace broken wheels or ring parts.
• Check for old food or melted plastic stuck under it.
• Keep the microwave clean to avoid this problem.

Inspect the Waveguide Cover

There is a small part inside your microwave that most people never notice. It’s called the waveguide cover. It is usually a small, square, plastic-looking plate inside the wall of the microwave. I never paid attention to it until I saw it turning brown and giving off a burnt smell.

The waveguide cover protects the microwave’s inside parts from food splashes. But when food or oil splashes on it, it can burn the cover. And then, it will smell like burning plastic every time you use the microwave.

If your microwave smells weird, look at the waveguide cover. Is it brown, dirty, or has a hole? If yes, you need to replace it. It’s not very expensive, and you can do it yourself.

To replace it, unplug the microwave. Remove the screws (if any) holding the cover. Carefully take it out and put a new one in the same place. You can order the same model cover online.

Also, always cover your food with a paper towel or microwave lid. This will stop splashes from going to the waveguide.

• Waveguide cover can burn from food splashes.
• Look for brown spots, damage, or holes.
• Replace it if it’s burnt or dirty.
• Always cover food while heating.
• Keep the inside walls clean.

Smell from Worn Out Internal Parts

If your microwave is not new, and there are no melted plastics inside, the smell might be from old or broken parts. Microwaves have wires, fans, and small motors inside. Over time, these can wear out, overheat, and smell like burning plastic.

This happened to my old microwave. It was 5 years old, and one day I noticed the plastic smell again. I checked inside — everything looked clean. But when I used it, I could still smell it. So I opened the back cover (after unplugging it) and saw the wires near the fan were dark and melting.

When plastic on wires or motor covers starts to break, it smells really bad. It can also be dangerous. It’s a fire risk. You should never keep using a microwave if the inside parts are burning or melting.

In this case, the best thing to do is call a repair person or replace the microwave. Don’t try to fix it yourself unless you know what you’re doing. Electricity inside a microwave can be very dangerous.

If the microwave is old, it’s sometimes cheaper and safer to buy a new one than repair it.

• Old wires or motors can smell like burning plastic.
• Smell can come from inside the microwave body.
• Stop using it if smell continues after cleaning.
• Call a technician or replace the microwave.
• Don’t try to fix internal parts by yourself.

Clean and Deodorize Deeply

Even after fixing the cause, sometimes the smell stays in the microwave. This can be super annoying. I cleaned everything, but still every time I opened the door, the burning smell was there. That’s when I learned how to clean it deeply and remove the smell fully.

First, unplug the microwave. Take out the glass plate and wheels. Wash them with soap and hot water. Then, inside the microwave, use a mixture of baking soda and water. Scrub all the walls, roof, and floor of the inside with a soft sponge.

Then, do this trick: fill a bowl with one cup of water and 2 tablespoons of lemon juice or vinegar. Put it in the microwave and run it for 5 minutes. The steam from this mix helps loosen smells and clean spots.

After that, wipe everything inside again with a clean cloth. Keep the door open for a few hours. You can also place a bowl of dry baking soda inside and leave it overnight. It helps absorb any smell left.

Do this deep cleaning every few weeks to keep your microwave fresh.

• Wash all removable parts with hot water.
• Scrub inside with baking soda and water.
• Steam clean with lemon juice or vinegar.
• Wipe dry and leave door open to air out.
• Use baking soda bowl overnight for bad smells.

Final Thoughts

If your microwave smells like burning plastic, don’t ignore it. It could be something small, like a melted lid, or something serious, like burnt wires. Always check inside, clean it well, and use only safe containers. A clean microwave not only smells better but also keeps your food safe. Fixing this issue quickly saves you money and gives you peace of mind.

Frequently Asked Questions (FAQs)

Is it safe to use a microwave that smells like burning plastic?

No, it is not safe. A burning plastic smell can mean that something is melting or overheating inside your microwave. It could be a plastic container, a food wrap, or even the inside parts of the microwave like wires or the waveguide cover. Using the microwave in this condition can cause fire or release harmful fumes. Always stop using it and check the cause of the smell first.

Can I remove the burning plastic smell from my microwave?

Yes, you can. First, clean the microwave fully. Take out the turntable and wheels and wash them. Then scrub inside using baking soda and water. You can also steam clean it using vinegar or lemon juice and water. Wipe it dry and leave the door open to air it out. Place a bowl of baking soda inside overnight to absorb the smell. Repeat this a few times if needed.

Do I need to replace my microwave if it smells burnt?

Not always. If the smell is from melted food or plastic containers, cleaning might solve the problem. But if the smell is coming from burnt wires or motor parts inside the microwave, you may need to replace it. Microwaves with broken internal parts can be dangerous. If your microwave is old and smells burnt even after cleaning, replacing it is often safer.

Is it okay to microwave plastic containers?

Only if they are labeled microwave-safe. Many plastic containers can melt or release harmful chemicals when heated. Always check the bottom of the container. If it does not say microwave-safe, do not use it. It’s better to use glass or ceramic containers for heating food. Using the wrong plastic can damage your microwave and cause bad smells.

Can I fix the waveguide cover myself?

Yes, in most cases you can. The waveguide cover is usually easy to remove and replace. First, unplug the microwave. Then take out the old burnt cover by removing the screws or sliding it out. Buy the same model cover and place it in the same spot. Always make sure it fits properly. This will help prevent future smells and keep your microwave safe.

Do I need to clean under the microwave plate?

Yes, you do. Food crumbs, sauces, or even pieces of plastic can fall under the plate. If these melt or burn, they create strong smells. Take out the plate and wheel ring, and clean underneath. Use baking soda and warm water to scrub gently. Doing this often will stop bad smells from coming back.

Is it normal for a new microwave to smell?

Yes, sometimes it is. New microwaves often have a plastic or paint smell when first used. This comes from factory materials heating up for the first time. The smell should go away after using it a few times with water. But if the smell gets stronger or doesn’t go away, stop using it and check for any problems.

Can vinegar help remove smells from the microwave?

Yes, vinegar works very well. Mix one cup of water with two tablespoons of vinegar in a bowl. Heat it in the microwave for 5 minutes. The steam from this mix loosens smells and helps clean the inside. After it cools, wipe everything clean. Repeat this if the smell is still there. It’s safe and natural for cleaning.