Having a microwave makes your cooking quicker and safer but sometimes your microwave is overheated and you don’t know why. To find the reason of overheated microwave and how fix it, stay with me in this post.
Every microwave oven comes with a user manual that contains instructions on how to operate the microwave in an ideal way.
If you use your microwave as per instructions given in the user manual, the chances of microwave overheating are rare. You should consider one more fact that your microwave is an electronic appliance like any other kitchen appliance, so it can get overheated or start malfunctioning on some day.
How Do I Know If My Microwave is Overheating?
You use the microwave everyday to prepare breakfast and lunch or dinner. It does the cooking and reheating job properly, so how you can realize when your microwave is overheating, right? Well, this is where your observation can be useful.

When your microwave is overheating, it will show up one or more kinds of malfunctioning. Here I provide some common issues that arise when a microwave overheats.
Feels Too Hot to Touch:
You should touch the microwave from outside after the cooking is over. If your microwave feels too hot to touch on outside, it must be overheating. Please don’t touch the interior of your microwave as the interior takes a few minutes to cool down after each cooking process.
Auto Shut Off Too Often:
The microwave comes with built-in auto shut off feature that keeps it safe. The auto shut off feature turns off the microwave when it’s not in use for a few minutes.
The auto shut off also turns off the microwave when there is power supply or high voltage issue or when the microwave is overheated. If your microwave often shuts off automatically, overheating can be the problem.
Cooling Fan Runs Longer than Usual:
Your microwave has a built-in cooling fan that runs with every cooking process. The fan runs to cool down the magnetron of the microwave. The magnetron generates electromagnetic heat waves to cook the food in the microwave, while the fan throws cool air to cool down the magnetron and other important parts.
When you cook something in your microwave, you can hear the fan noise. If the fan runs longer than usual then you should realize that your microwave is overheating.
Food is Overcooked or Burnt:
After a few months, you know how powerful your microwave is and how much time it takes to cook the food. If your microwave overcooks or burns food even if you set the timer as usual, it can have the overheating issue.
Also Read:- How to Set Clock on a Microwave
So, these are some important points that you should notice to know if your microwave is overheating.
Why is My Microwave Overheated Too Often?
Earlier, overheating was a common issue with the microwaves. The manufacturers do everything they can to fix and prevent the issues customers face with the microwave. At present, the microwave shuts off automatically if it has any overheating issue, so it fixes the problem by itself. But that doesn’t mean that the microwave can never overheat, it does.

A microwave can overheat because of different reasons, here I will share all possible reasons for microwave overheating problem as follows.
#1. Running Microwave for a Long Period:
You can cook and reheat all types of food and beverage in your microwave but you should not run the microwave for a long period. For example: If you run your microwave continuously for 1-hour, it can cause the microwave overheating issue.
So, your microwave can get overheated if you keep it on for an extended period. I strongly recommend you to refer the user manual of your microwave to know how long you can continuously run the microwave and never exceed its limit.
#2. No Moisture in Food:
The microwave generates electromagnetic waves that revolves in the cooking area. These waves vibrate water molecules inside the food to heat up and cook the food. If the food does not have any moisture, it won’t absorb the heat waves much.
The food with no moisture takes longer to get cooked in the microwave. Not only that, the microwave has to generate more heat to cook such food which can also cause overheating of the microwave.
#3. Inside Food Generate So Much Steam:
The food with high moisture or water often releases more steam during the cooking process. When you microwave such food, the heat waves will start cooking the food and it will release so much steam inside. This increased steam causes your microwave to overheat itself and the food.
#4. Metal Bowl/Container Inside Microwave:
The metal bowls and containers are not recommended to use in the microwave. Because the heat waves cannot penetrate metal which prohibits the microwave to cook/heat up food from sides. So, it can cook the food from top only and it will take longer to do it.
The heat waves can’t pass through metal, so they keep hitting the microwave walls. As a result, the cooking area (interior of microwave) begins to overheat. Don’t use a metal bowl or it will cause your microwave to overheat unnecessarily.
#5. Poor Venting or No Venting:
The microwave needs some free space on both sides as well as on top and/or back for ventilation. The microwave generates heat waves to cook food inside and it needs ventilation to release excess heat out. If the venting is clogged, it can cause microwave overheating issue.
At the time of installation, you should leave necessary space around your microwave for venting purposes. If you don’t provide proper venting to your microwave, it will overheat itself and overcook or burn the food as well.
#6. Cooling Fan Problem:
The microwave has a built-in cooling fan inside. The fan runs continuously to throw cool air on magnetron and other parts of the microwave. If the fan slows down or does not function properly, you will notice that your microwave is overheated easily.
When using your microwave, you should notice the noise of its fan. If you find any change in the noise then you should know that the fan is the reason for your microwave overheating issue.
Also Read:- How to Silence Your Microwave
#7. Magnetron Malfunctioning:
Magnetron is the most important part of your microwave. It generates all heat waves/microwaves needed to cook the food. If the magnetron generates heat more than needed, it means that it’s malfunctioning and can cause overheating issue with your microwave.
#8. Receiving High Voltage:
There are several electronic components inside the microwave. These components receive AC power from the cord connected to wall outlet and covert it into DC (direct current) as needed by the microwave.
If an internal component malfunctions, it will affect the whole power supply of the microwave. The microwave needs 110V or 120V from the wall outlet, if it receives more than needed electricity power then it will cause microwave overheating and malfunctioning problems.
#9. Microwave Stay On with Opened Door:
There are 3-4 switches attached to the microwave door. The switches prevent the microwave to turn on when the door is opened and turns it off when you open the door. If one or more switches are broken, the microwave will stay on even if its door is open. It can also cause overheating.
In this way, a microwave can get overheated by one of the above given reasons. You should check it yourself to know what’s the exact reason for your microwave overheating issue.
How to Fix an Overheating Microwave
You can fix an overheating microwave after you find out the reason for its overheating. I have explained all possible reasons for the microwave to overheat abnormally so that you can use them to find a fault in your microwave and fix it ASAP.
The microwave can get overheated for two types of reasons called technical issues and non-technical issues. You can fix the non-technical issues of the microwave by yourself but need to hire a technician for fixing the technical issues.
[A] DIY: Fix an Overheating Microwave
- If there is no moisture in your food i.e. the food is very dry, you should not put it in the microwave. You can microwave it after adding a few drops of oil or water.
- If the food is going to generate too much steam, don’t cook it in the microwave. You should cook it on a stovetop or other ways.
- Make sure that there is enough venting space around the microwave. In case the microwave venting is clogged, clean it immediately.
- Check the door switches of your microwave. If one or more switches are broken, replace them with brand new switches.
- Check the microwave power cord, replace it if the cord is cut or damaged.
[B] Hire a Technician to Fix an Overheating Microwave
The technical problems of the microwave occur rarely but you cannot fix them by yourself. In order to fix such issues, you must have complete knowledge about microwave hardware and enough skills to open the microwave with required tools.
If your microwave fan is malfunctioning or magnetron is overheating or it has high voltage issue then it’s time to call up the technician. The technician will open the microwave and check for the problem. Then s/he will repair it properly and replace one or more parts if needed.
Sometimes, the microwave is overheated for unknown reasons. You try to find out but cannot find the actual reason for your microwave is overheating. Don’t worry, you can still hire a technician to find the fault and repair the microwave with proper care.
How to Prevent My Microwave from Overheating in Future
My friends often ask me how they can keep their microwave from overheating. I have a long experience of using microwave, so I have some simple suggestions to prevent your microwave from overheating in future.
- Never run the microwave for an extended period. Always give a break of 15-20 minutes between two cooking cycles so that the microwave can cool down before you get it in use again.
- Never put a metal bowl or metal plate or metal container in the microwave as the metal is not safe to microwave.
- Never cook any food that generates too much steam inside the microwave.
- Don’t put any dry food (no-moisture food) in the microwave without adding some cooking oil or water.
- Clean the microwave once a week and clean its venting once a month.
- Check the door switches time to time and replace them when broken.
In this way, you can prevent your microwave from overheating in future and extend its lifespan for a few more years.
What Should I Do When My Microwave is Overheated?
You should unplug your microwave when it is overheated. The microwave gets heated inside and feels warm on its outer surface. When you touch the exterior of your microwave, you should feel warm during use and also up to a few minutes after use.
Being warm is normal for the microwave but it should not feel hot when you touch its exterior. If your microwave is overheated, you should immediately remove its power cord from the wall outlet. Don’t waste your time in thinking, just unplug the power cord to stop the power supply to your microwave.
If the microwave is too hot then open the door and windows of your kitchen. After removing the power cord, let the microwave cool down for 15 to 20 minutes. Once the microwave reaches room temperature, plug its power cord back and turn it on to cook/reheat something.
You should monitor the cooking process to know if the microwave works normally or not. If the microwave overheats again then you should unplug its power cord and call up a technician to get your microwave checked & repaired properly.
Can My Microwave Catch Fire Easily?
No, your microwave cannot catch fire easily. The microwave brands add all safety and emergency features in the microwave so that it does not catch fire. If your microwave is overheated, it will turn off by itself using its auto shutoff function.
In present time, most microwaves come with the overheating protection that prevents it from catching fire. Your microwave also has a thermal fuse that gets blown in case high voltage or power supply issues. The thermal fuse saves the microwave from further damage to the magnetron and other parts.
The chances of your microwave to catch fire are very rare but it still can catch fire. You should use it ideally and don’t put anything in the microwave if it’s mentioned as “not-safe” by the manufacturer.
FAQs about Microwave Overheating Issue
In order to find the overheating issue in your microwave, you should take care of how you use it. In case you have any question or query about microwave overheated, I have covered it in the following FAQs. Kindly, read all questions and answers to clear your confusion.
Q.1 Will a microwave shut off if it overheats?
Yes, a microwave will shut off if it overheats because it has a thermal fuse inside that monitors the heat level of the microwave and shuts it off when it overheats.
Q.2 What causes a microwave to overheat?
There are various causes for a microwave to overheat including poor or clogged venting, faulty fan, high voltage, extended use and others.
Q.3 What happens if a microwave overheats?
The microwave automatically shuts off when it overheats but sometimes if a microwave overheats, it overcooks or burns the food inside.
Q.4 What causes a microwave to suddenly stop working?
Overheating causes a microwave to suddenly stop working but you can turn it again soon after the microwave cools down. The ceramic fuse or thermal fuse blown out can also cause a microwave to stop working, so you need to check the issue whenever it happens.
Summary: Wise Cooking, No Overheating
You can take care of your microwave by using it appropriately. It can save your microwave from unnecessary damages caused by overheating, sparks and fire in rare cases. You should always use a microwave-safe plate/bowl so that it does not affect your food or damage the microwave in long term.
When you need to cook so much food at once, leave your microwave idle for 15 minutes between each cooking cycle. Don’t run the microwave continuously for an extended period as it can cause overheating, malfunctioning and damage its internal components.
My last advice to you is that you should provide proper ventilation to your microwave. You should also check and clean the venting at least one time in a month. With appropriate use and proper venting, your microwave will work like new for years.