Microwave Is Hot When Not In Use – What To Do?

Is your microwave overheating even when you’re not using it? Are you not sure what to do when this happens? If you are finding yourself in this situation and are looking for some solutions to troubleshoot this issue, this article can help give you a few different routes to try and figure it out.

When a microwave becomes hot when not in use, there are a few things that can be done to determine what the cause is. That includes immediately unplugging it from the outlet, monitoring it when to note when it gets hot, checking the power cord and the fan, and assessing the diode and the magnetron.

To learn more about how to go about each of these troubleshooting methods, keep reading.

Unplug the Power Source

The very first thing you should do when your microwave is getting hot even though it isn’t actively in use is to unplug it from the power source. The majority of the time, that is going to be via a power cord that is connected to the appliance and plugged into an outlet on the counter or in the wall.

First, identify where that power cord is located and then detach it so it doesn’t have access to power, which means it can no longer heat up. Do this with extreme caution, as the microwave will be hot even though it is not turned on. It would be smart to wear oven mitts or use pot holders to protect your hands from the heat and keep you from potentially getting burned.

Be careful to not use the microwave if it feels even slightly hot to the touch and hasn’t been in use for a while. This can cause worse damage to the microwave and create a more dangerous situation.

Monitor When the Microwave Gets Hot

The next step is to monitor the microwave. Do not leave it alone once you have unplugged it from the power outlet. After you have unplugged it, wait for about 10-15 minutes and feel for heat on the microwave on all sides, both inside the microwave and outside. When you are doing this, you are going to want to pay special attention to the areas of the microwave that are particularly warmer than others. This can give an indication as to where the majority of the heat is coming from, which will allow you to assess what part of the microwave may be overworked or malfunctioning, causing it to overheat.

If you find that the microwave is all around still equally warm, wait another 10 minutes or so. The area that is the most overworked will be warm longer than the rest of the microwave, so you will be quickly able to tell where to continue searching for the issue.

Look at the State of the Power Cord

Once you have unplugged the microwave from the power source and assessed where the majority of the heat is coming from, it is now necessary to check the state of the power cord that you just unplugged. The main producer of power as well as the heat is the power cord. First, look at how the cord is attached to the actual microwave and make sure the wiring and casing are all intact with no bending or cracking, especially at the head of the cord.

If there is any visible damage at the head of the cord on either end, whether it be the microwave end or the outlet end, that could be a concentrated area for electricity and heat to build up, making the microwave retain the heat it produced when it was in use. If the power cord is damaged, replacing it will likely fix the issue.

Check the Health of the Fan

After you look at the power cord, check how the fan is doing. To do this, you will need to use your microwave’s owner’s manual to locate the fan that is on your microwave, as they are typically located on the back panel, but some are in different locations depending on the brand and model you have in your kitchen. It is important you do each of these steps in order, but it is especially important that you do this step after unplugging the microwave so the fan is off if it is still functioning properly.

Once you access the fan, slowly spin the fan in either direction and make sure it can spin around the complete area of the panel. If it doesn’t, make sure to remove anything that would be keeping it from doing so. If your fan is rusted, it may be a sign that you need to replace your fan. Once the fan is replaced, put the back panel securely onto the microwave.

Assess the Diode

Once you have assessed the fan, the next step in troubleshooting this issue is making sure the diode is functioning properly. The diode is the part of the microwave that allows the electricity coming from the power cord to power the microwave. That being said, if the diode is malfunctioning and not converting electricity properly, that can lead to either too much or too little power being used to power the microwave, which is a problem.

To test the functionality of the diode, you will need to do a few things to prepare. First, you will not be able to safely access the diode in the control panel until the microwave has been unplugged for at least 24 hours. You will also need to have a multimeter on hand to be able to determine the health of the diode and make the call on whether it needs to be replaced or not.

Evaluate the Magnetron’s Performance

If the diode is performing just fine, the next and last resort to find the cause of your microwave overheating is to evaluate how the magnetron is performing. The magnetron can be evaluated by removing the circuit board from the electrical panel on the back of the microwave. The panel will have to be disassembled to access the magnetron.

Once you access it, you will need to use the multimeter to test on an open circuit. If you hear loud beeping coming from the multimeter, your magnetron is working fine and you will not need to replace it.