3 Common Frigidaire Microwave Exhaust Fan Problems Fixed!

Though Frigidaire microwave exhaust fan problems often appear the hardest to fix, they are usually the easiest. You only need to recognize the cause and address it DIY, and that’s where this simple troubleshooting guide jumps in. 

Some commonest Frigidaire microwave exhaust fan issues include the exhaust fan not working, the exhaust fan failing to turn off, and the exhaust fan turning on by itself. 

So, our focus today is on those three issues, which cost a lot of money to fix if you contact a microwave repair service. Interestingly, some of their causes are related, meaning you may master how to fix more than one problem by addressing one issue. 

For example, by addressing the thermostat or filter issue, you can fix an exhaust fan that won’t work or runs nonstop. Likewise, you can address both problems by replacing the fan motor. 

Let’s jump into the issues and address them!

Frigidaire microwave exhaust fan problems

In a hurry? Consider the Frigidaire microwave exhaust fan guide below.

Quick Frigidaire Microwave Exhaust Fan Troubleshooting Guide 

Problem Likely Cause Applicable Fix 
1.Frigidaire Microwave Exhaust Fan Won’t Work A clogged filter or a defective exhaust fan motor, microwave thermostat, control panel, touchpad, or main control boardClean a filthy grease filter and replace a clogged air filter or faulty exhaust fan motor, microwave thermostat, control panel, touchpad, or main control board
2.Frigidaire Microwave Exhaust Fan Won’t Turn Off  Microwave overuse, poor ventilation, clogged filter or a defective thermostat, fan motor, damper assembly, or control boardDon’t overuse the microwave, improve the kitchen’s airflow, clean a filthy grease filter, and replace a clogged air filter or defective thermostat, fan motor, damper assembly, or main control board
3.Frigidaire Microwave Exhaust Fan Turns On By Itself Cool-down phase or a defective switch or control boardAllow the microwave time for the cool-down phase to end, and replace a faulty switch or control board

Troubleshooting Common Frigidaire Microwave Exhaust Fan Problems

Shared below are 3 of the most typical Frigidaire microwave exhaust fan problems you can fix:

1. Frigidaire Microwave Exhaust Fan Not Working

The Frigidaire microwave exhaust fan doesn’t stop working for no reason. Something must be wrong for the fan to fail, and in most cases, it’s one of these issues:

a) Clogged Air/Charcoal or Grease Filter 

Frigidaire microwaves come with two filters: an air (or charcoal) filter and a grease filter. The air/charcoal filter, present on over-the-range Frigidaire microwaves, absorbs pollutants that build up over the filter and clogs it, and once that happens, the exhaust fan cannot run. 

Meanwhile, the grease filter absorbs grease (fats & oils) from the heated food to protect the exhaust system from obstruction. It, however, clogs up over time, just like the charcoal filter. 

Once that happens, the exhaust system also starts clogging, and as a result, the exhaust fan is unable to run. 


Locate the charcoal filter behind your microwave exhaust outlet grill. You may require to take down the grill to access the filter. If the charcoal filter is clogged up, replace it. You’ll also need to replace it if it’s damaged. 

And unlike the charcoal filter, which you should replace if it’s clogged, you should clean a clogged grease filter. Preferably use hot water with dishwashing detergent. 

b) Defective Exhaust Fan Motor 

The exhaust fan motor won’t turn on the fan blades if faulty. Once that’s the case, your microwave’s exhaust fan system will fail. 


Unplug the microwave and take out the fan motor. Then try to turn the fan blades manually (by hand). If the blades won’t spin freely, that suggests a defective fan motor. But just to be sure, test the fan motor with a multimeter. If it shows no continuity, replace it. 

c) Defective Microwave Thermostat 

The microwave thermostat’s job is to monitor the air temperature and switch on the exhaust fan. It’s unable to do that when it’s faulty, which stops your microwave fan from working. 


Also, use a multimeter device to check if the microwave thermostat has continuity. If it doesn’t, that indicates it’s defective. Thus, replace it. 

d) Faulty Control Panel, Touchpad, or Main Control Board

Though the least likely reason; your Frigidaire microwave exhaust fan might not be working because of a non-working control panel, touchpad, or main control board. 

If the fan indicator light won’t come on when you press the touchpad, then it’s likely that the touchpad is defective, and when the light doesn’t show up when you press the control panel, the control panel could be faulty. And if it’s neither of the two, it could be the main control board. 


Try pressing the control panel and touchpad buttons to see if the fan will indicate. Suppose it doesn’t, then replace the affected part. But if the issue has nothing to do with the touchpad or control panel, replace the control board. 

Frigidaire microwave exhaust fan not working

2. Frigidaire Microwave Exhaust Fan Keeps Running

Sometimes the Frigidaire microwave exhaust fan won’t stop running or turn off when you try switching it off. If so, here are the possible triggers. 

a) Microwave Overuse 

Your Frigidaire microwave needs a break. You can’t run it all day and expect it to be okay. These appliances have a thermostat whose job is to turn off the microwave when it needs cooling. 

It, however, becomes more complex for the thermostat to do its job if you are using the microwave back to back, and the microwave will therefore take much longer to cool off. 


Just stop using the microwave nonstop. Give it some time (5 – 10 minutes) to cool down before re-running it. 

b) Poor Ventilation (The Kitchen Could Be Too Hot)

The other issue is that your Kitchen might lack adequate ventilation, thus feeling too hot. Once that’s the case, it becomes difficult for your Frigidaire microwave to cool down. 

That’s why it’s advisable to position the microwave where there’s some ventilation, even near a window. 


Improve your kitchen’s ventilation to ensure it’s not too hot when the microwave is running. Consider placing the microwave near a window or small gaps in the kitchen. 

c) Clogged Filter 

Your microwave exhaust fan might fail to turn off because of a clogged grease or air/charcoal filter, which I discussed earlier. 


Consider washing the grease filter with hot water and dishwashing soap. It’s heavily greased. As for the air filter, consider replacing it if it’s dirt clogged. 

d) Defective Component 

In particular, your microwave fan will run nonstop if any of the components below is faulty:

  • Thermostat – If the thermostat is defective, it cannot monitor the air temperature, which means the microwave might run nonstop. Check it with a multimeter to see if it lacks continuity (a sign of fault).
  • Fan motor – A defective fan can also run nonstop, and you can check it using a multimeter or manually. If the motor lacks continuity or doesn’t turn the fan blade manually (by hand), it’s faulty.  
  • Damper assembly – The damper assembly blocks the outside air from entering the fan exhaust system. If it fails, air will enter the exhaust system, causing the fan to run nonstop. 
  • Control board – Lastly, if your microwave fan has no power, it’s most likely because the control board is no longer working. 


Consider getting a replacement for any of the above Frigidaire microwave components (View on Amazon) if it’s faulty. As for the damper control, you may need to get a Frigidaire microwave exhaust adapter. The existing one could be obstructed or damaged. 

3. Frigidaire Microwave Exhaust Fan Turns On by Itself

Sometimes the microwave exhaust fan switches itself on. That’s normal when you are using the under-microwave stovetop for cooking. In such a case, the microwave goes through a brief cool-down phase and turns the exhaust fan when the stage ends. 

However, if this happens when you aren’t using the stovetop, it could indicate a major component failure. In particular, it could point to a:

  • Defective door switch or interlock switch 
  • Failed control board 


Test the door switch and interlock switch to see if they’ve continuity. If they don’t, replace them. And if the issue is not the switch, replace the control board. 

Frigidaire microwave exhaust fan won't turn off

People Also Ask 

1. Why Does My Microwave Exhaust Fan Not Shut Off?

Your microwave exhaust fan won’t shut off because you are overusing it, there’s no adequate ventilation in the kitchen, or the air or grease filter is filthy. 

And if that’s not it, it could be due to a defective thermostat, fan motor, damper assembly, or control board. 

2. What Are the Reasons for A Microwave Fan Not Working?

There are different reasons why the microwave exhaust fan won’t work. They include a clogged filter and a defective exhaust fan motor, control panel, thermostat, touchpad, or main control board. 

3. Does A Microwave Need an Exhaust Fan?

All microwaves need an exhaust fan for ventilation. It helps to eliminate the excess heat that builds up when the microwave runs. Therefore, you should regularly inspect the exhaust fan system to ensure it works. 

4. Why Does My Microwave Exhaust Fan Turn On When I Use the Microwave?

Microwaves have a built-in thermometer that monitors the temperature and turns on the exhaust fan when the microwave is too hot. This is an automatic response by the microwave that helps to protect it from overheating. 

Closing Thought 

Discussed are the most everyday Frigidaire microwave exhaust fan problems to fix yourself. Consider the guide when the exhaust fan won’t work or stop or an option that turns on itself. Do that before asking for expert help which will cost you money. 

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