How To Improve a Microwave Exhaust Fan That Doesn’t Work Well

As a person who loves to cook, a microwave is one of the cooking appliances you would not want to miss. It is a kitchen appliance that saves time when warming food.

When my microwave starts misbehaving, the first component I check is the exhaust fan if it’s running smoothly.

The most known causes of exhaust fan defects are grease, oil, or fats that might have clogged the exhaust system. Electric circuits may also be another reason.

Fixing your microwave exhaust fan should not be a problem, but it does not mean it is an easy job. The following tips might be of much help during the reparation of the fan.

How to Improve a Microwave Exhaust Fan That Doesn’t Work Well

Check the Charcoal Filter

A charcoal filter traps and absorbs smell from the food when external ventilation is unavailable.

When the filter is not functioning well, poor air circulation in the microwave is a common issue that hinders your ability to enjoy food without foul odors.

Apart from preventing foul odors, the charcoal filter ensures the optimum functioning of the microwave exhaust fan.

The filter is usually located near the top of a microwave at the back. You may want to consult your manual to know the exact position of the filter.

The following is how you can check a charcoal filter for faults;

  • You may need a screwdriver to access the filter.
  • The second step is to locate the filter at the back of the microwave near the top, behind the exhaust air outlet grill.
  • Unscrew the exhaust air outlet grill to access the filter. Draw the filter and check for damages or built-up debris.
  • If your charcoal filter is damaged, blocked, or has surpassed producers’ replacement guidelines, you may want to consult your manual. Otherwise, you should be able to clean it up and fix it back.

Inspect Grease Filter

A grease filter is another microwave component that absorbs oils and fats when warming food.

This mechanism ensures the exhaust fan works efficiently by keeping the exhaust system clear of oils and fats, preventing them from clogging the fan.

It is a known problem for grease filters to clog, and more often, it needs replacing.

How you can inspect your microwave grease filter;

  • Locate the grease filter at the bottom of the microwave, held by spring clips
  • Unclip the filter and check for grease deposits. You can clean simply using water and soap
  • If the filter is damaged, you will need to replace it

Examine the Damper Assembly

The damper assembly is an essential part of a microwave that prevents exterior air from getting in through the exhaust system.

When your exhaust fan stops working correctly, it may be because of this critical component.

The damper assembly is a flap made of plastics and metal that closes and opens to seal the exhaust duct. The flap opens when the fan is on and closes when it’s off.

When examining the damper assembly;

  • Disconnect your microwave from the main power supply
  • Remove the microwave from its place if possible or necessary
  • Check for objects that could be hindering the flap from opening and closing
  • It would help if you also looked for physical damages, signs of wear, or cracks on the flap
  • You may want a replacement in cases where repairing is not an option

Look at The Fan Motor

The fan motor is the most crucial component of the microwave exhaust fan. It helps circulate the air through the exhaust system.

Mostly, the fan motor could be why your exhaust fan is not working well. Due to this, it’s essential to test the fan motor to conclude if it is working correctly.

How you can survey the fan motor;

  • Unplug your microwave and remove it from the wall
  • Find the fan motor, usually at the back of the microwave near the top
  • Remove the fan motor and rotate the engine manually. If it is not turning, you may need a multi-meter to test it
  • Set your multi-meter to Rx1 and touch the motor’s terminals with the probes. You should be able to receive a reading of 0 to show there is continuity
  • If there is no continuity, you should consider replacing the fan motor


A microwave is an essential device in the kitchen that saves time more often. It would be best to keep its exhaust fan at maximum efficiency to allow its proper functioning.

You should do proper maintenance to supporting components of the exhaust fan like a charcoal filter, grease filter, damper assembly, and fan motor to keep the exhaust fan function at its peak.

Using this article, you should be able to improve your microwave exhaust fan.