How to Fix a Microwave Fan That's Not Working

If your microwave exhaust fan stopped working, the issue may be a clogged charcoal filter. This type of filter is used in over-the-range microwaves, to absorb smells and pollutants from heating food. These pollutants will build up over time and cause the filter to become clogged. Make replacing the charcoal filter on your microwave a regular part of your home maintenance routine. To reach the filter, which is normally located behind the exhaust air outlet grill, take off the drill by removing its screws and remove the filter. Insert the new filter, using the spring clip to secure it if applicable.

If your microwave exhaust fan has stopped working, it may be because the grease filter is clogged. The grease filter traps oils and fats from food that is being heated, to keep the exhaust system clear. It is common for grease filters to become clogged over time and need replacing. Grease filters are typically located at the bottom of the (over-the-range) microwave, and are held in place with spring clips. You can remove your grease filter and clean it with water and dish soap, although it may need to be replaced entirely if the buildup is too stubborn to clean.

If your microwave exhaust fan is no longer working, the damper assembly may be causing the problem. The damper is a component in over-the-range microwaves that prevents exterior air from entering through the exhaust system. The damper is a flap made of metal or plastic which seals the exhaust duct when the fan is off, and opens up when the exhaust fan is running. The flap is often spring-loaded, or may be designed so that it simply opens and closes relying on gravity. To access the damper assembly, you may need to remove the microwave from its place in the wall or cabinet which it is built in to. Check for any objects that could be keeping the damper from opening and closing, and check for damage. Replace the damper is necessary, and take care to reinstall the duct work so that it does not block the damper in the future.

The exhaust fan on your microwave may not be working because of an issue with the fan motor. This part is a component of over-the-range microwaves, and helps circulate the air through the exhaust system. To inspect the fan motor, first unplug the microwave and remove the microwave from the wall or cabinet. The fan motor is usually located in the back of the microwave, near the top. Remove the fan motor cover and try rotating the motor manually. If it does not turn, you should replace it. If the fan does turn, test it using a multi-meter. Replace the fan if it shows no continuity. If the fan shows continuity, the last option would be to have a live voltage test performed by a qualified technician to see if the fan is receiving power.