A microwave is an appliance that you’ll find in most kitchens around the world. It’s used to heat foods, but it can also be used for many other things.
The fan inside the microwave is what circulates the air, so your food heats evenly — and it shouldn’t turn off unless you’ve set a time for something to cook on auto-defrost or reheat mode.
If you have a microwave oven that is unable to shut off, it is a sure sign of a serious problem. There are various reasons for this behavior.
In some cases, the fan continues to run because there is no power going to it or due to an open door switch. A broken magnetron inside the unit might also be the cause of the problem.
A bad inverter that converts mains voltage into high-frequency pulses can also turn on the fan indefinitely until fixed by a technician.
If you are looking to get answers to why your microwave fan won’t turn off and more, you are in the right place. So let’s get to it.
What Causes Microwave Fan Not to Work
- The most common reason for a microwave fan to stop working is due to the thermal fuse malfunctioning. Your microwave will no longer heat food if this happens, but it will still run using its ventilation system. Unfortunately, this causes the microwave to blow warm air throughout the room and deter you from using it at all.
- Another possible cause of a non-working fan is if debris or dirt has built up in the microwave.
- The microwave is turned off – This is one of the most common causes for an oven not turning on at all. Make sure that you turn on the microwave before using it.
How to Fix Microwave Fan That Does Not Work (Step by Step Process)
Step 1 – Check the Air Filters
The first step is to remove any obstructions that might be preventing the air from circulating through the filter.
Remove anything that may be blocking airflows, such as paper towels or plastic wrap. Also, check for dirt and debris around the filter; if there are any, then use soapy water to clean the metal case or replace it if it’s worn out.
If there are no obstructions, then it’s time to check for other common issues that cause the microwave not to work.
Step 2 – Check the Grease Filter
Microwave grease filters are specially designed to filter excess fat and oil from your prepared meals so that you can enjoy your meal without thinking about how many calories it contains.
The filters are made of thin fabric coated with a safe non-stick surface. However, when the grease filter is no longer working, you will need to take some actions to fix it.
First things first, remove the microwave grease filter from the microwave oven. You may find that this is not an easy task if you have never done it before. There might be quite a few screws in place holding the filter in place within the appliance.
Remove the grease filter and use soap and water to remove the oily grease that is stuck around. Check for any damages in the filter and replace it with a new one in case there is a need.
Step 3 – Check the Damper Assembly
Damper assembly in a microwave helps the appliance block outside air from entering through the exhaust fan.
The component is typically a flap made of plastic or metal that opens the exhaust conduit when the fan is running and shuts it when it turns off.
If you suspect foul play by the damper assembly, inspect for items that may be preventing the component from properly opening and closing. Also, examine the damper visually for signs of cracking, wear, or damage.
Relace the damper incase there is any damage.
Step 4 – Check the Fan Motor
A defective exhaust fan motor will not turn, or it might make a squeaking sound. To find out if the fan motor is faulty, remove it and manually turn its blades.
If the blades don’t move freely, the motor needs to be replaced. On the other hand, if the fan blade turns freely but there is no power or continuity in it, the motor is fine.
Step 5 – Check the Thermostat
You should know that your microwave’s exhaust fan has a thermostat that monitors air temperature and turns on the exhaust fan when needed. Unfortunately, the thermostat may break down, causing the exhaust fan to function improperly.
If it doesn’t work, you won’t have proper ventilation. So, If you suspect a faulty thermostat, check for continuity. If there is no continuity, you should look for another thermostat as repairing the thermostat won’t be practical or worth your while.
Step 6 – Main Control Board
As stated above, the main control board going bad is a rare occurrence in a microwave. The most common cause of a malfunctioning fan is an issue with one of its parts.
The fan motor, wires, and various other components must be checked before the control board can be diagnosed.
If all these parts are fine and it’s still not clear why the exhaust fan is not working, call a technician to check out the control board.
Related Read: How to Fix a Microwave with a Trip Breaker
Precautions When Repairing Your Microwave
A microwave oven could be storing several thousand volts of electricity within its high-voltage capacitor, even when it’s unplugged.
This means your oven could “shock” you even if it’s not connected to power. Due to this electric shock possibility, it’s recommended you do not handle the equipment yourself or treat on the do-it-yourself repair.
If you do not have the proper tools or experience, then do not attempt to service the microwave. A licensed technician will be able to provide a proper diagnosis and repair.
What are the Symptoms of a Microwave that Won’t Turn Off?
- The microwave does not emit heat even after it has been turned on for more than 30 seconds.
- The display of the microwave remains blank even after you press any button on it.
- There is no response when you open or close the door of your microwave oven.
How to Troubleshoot your Microwave!
If your microwave won’t turn on, or if it does but blows a fuse when you do so, there may be an issue with the thermostat or magnetron.
The first thing to try is unplugging your appliance for ten minutes to see if this resets its internal circuits. If not, try replacing these parts under professional advice before anything else!
How do Microwaves Work?
Microwaving food is actually similar to what happens with radio waves. The microwaves travel through the air and into the microwave oven, where they bounce around until they hit any object.
If there is water or fat in that object, it will cause an effect called dielectric heating. This heats up the food to a very high temperature quickly.
Microwave Safety Tips
- Be careful while removing microwavable dishes from the oven as hot steam may escape. It is recommended that you wait till the dish cools down before removing it from the microwave oven.
- Cook food properly before placing them in a container or plate for heating through microwave radiation as uneven heating could.
The Different Types of Microwave Ovens
There are two types of microwave ovens available in the market: convection or combination microwave oven and conventional or standard microwave oven.
Standard microwave is an older version that heats only from inside, while convection microwaves cook both inside and outside simultaneously using radiant waves generated by electromagnetic fields.
Convection microwaves are also known as combination microwaves because they can be used for both functions.
Why Won’t My Microwave Turn Off?
Nobody knows why microwaves won’t turn off. Maybe it’s a conspiracy between the microwave and the light bulb companies, or maybe there is some new technology that we don’t know about yet.
Microwaves have been around for decades, but nobody has ever figured out how to shut them off. So when you press stop on your microwave, it starts up again as soon as you open the door.
Final Thoughts on Microwave Fan Won’t Turn Off.
A microwave fan that won’t turn off is a common problem in most microwaves. It usually happens when you try to set the timer, but it can also happen when you start the microwave with nothing inside.
The good news is that fixing this problem is usually pretty simple. Just follow the steps above, and you should have your microwave back up and running in no time!
We hope this article has been helpful for you! If there is anything else we can do for you, please let us know by leaving a comment below or visiting our website today.