Fixed: Why Microwave Fan Won’t Turn Off! 

Microwaves are becoming one of the most heavily used appliances in households these days. Owing to their continuous use, they have also become more prone to encounter minor glitches that might hinder their functioning properly. Sometimes after a long day with the microwave, you may find a continuous buzzing sound emanating from it, even after you have stopped working. This might be coming from the microwave fan that just won’t turn off. 

The problem isn’t a major one unlike instances where your microwave won’t heat at all; and is not a cause of much worry. However you may still find the reason behind why the microwave fan won’t turn off? This can be due to several reasons like the oven filters being unclean or clogged. The thermostat may become defective or the control board might have stopped working. The fan of the microwave is an important component that keeps it well ventilated. Hence any abnormality needs to be looked into and thereafter resolved. 

How to Know for Certain that Your Microwave Fan Isn’t Turning Off?

The microwave fan may keep working even after you have pressed the stop button. You may then unplug your appliance and do a proper diagnosis. If the microwave keeps running with the open door, the problem may be with the door interlock switch. Once connected to the switch, the latch of the door allows the microwave to operate once it has been activated. If the switch gets faulty it can allow the microwave to keep on operating even with the door open. 

Secondly, the microwave may keep running with the door closed. Such is the case that even pressing the stop button doesn’t help. The problem could be arising in one of the components of the microwave like thermostat, control board, or the switch may not be sending signals. 

Why Won’t My Microwave Fan Turn Off | Potential Reasons 

1. Your Kitchen Temperature May Just be too Hot 

Sometimes the temperature of your kitchen can be too high. At times, during the summer season, your microwave fan may refuse to run off. Then you can be patient and let the microwave cool down. In the heat, the fan shuts off automatically when the thermostat records a more even temperature between the microwave and room temperature. This it does to conserve energy. 

2. You Might be Overusing Your Microwave 

One reason why the microwave fan won’t turn could be that you’ve been using it way too much. Most microwaves, especially the GE ones have a thermostat installed which ensures that the fan doesn’t turn off until the microwave has cooled down completely. 

When the microwave is being overused, it takes it longer than usual to cool off resulting in an increased cooling time period. If that’s the reason then you probably need to wait sometime before the fan automatically turns off. This is completely normal since the fan won’t turn off until the thermostat records a cooler temperature closer to the normal. 

3. Your Microwave Might be Overheating

Sometimes you may notice that your microwave is getting hotter than usual. The reason could be because you may be overheating it. The signs could be that there are hot spots after you have used them for a while. 

If even without overusing it, the microwave gets heated easily, then you need to seek professional help. There’s a high chance that the control board is not functioning properly. Although this is highly unlikely to happen, one should still be careful. 

4. Faulty Main Control Board 

It’s very rare for the control boards to not function properly. However, after checking all the other parts like wires, thermostat, motor and other components, if nothing seems to be at fault, then the control board can be looked into. 

How to Fix a Microwave Fan that Won’t Turn Off 

Sometimes, the microwave fan may keep working long after the microwave has been switched off. The causes for this can be many. The major reason may be the thermostat and its functioning. There are a host of things which might have gone wrong. There are many simple methods which can be employed to fix the microwave fan conveniently. 

GE Microwave Ovens 

GE is one of the most common brands of microwave in the market, and this is due to its durability and affordability. When the fan of a GE microwave doesn’t turn off the reason usually is the thermostat. As soon as the thermostat senses any heat, it turns on the microwave fan. The thermostat of the GE microwave is known for failing often and everytime it does fail, the microwave fan has to run. When the fan doesn’t turn off with the microwave, you can try the following tricks: 

• Visit the control room and press control setup. You can also choose the options button and the microwave display will enter the setup mode. 
• Scroll to the ‘vent fan’ sub-menu and press the enter option. Then select ‘off’.
• After this press the enter button once again. This should turn the vent fan. 

Samsung Microwave Ovens

Another outstanding brand in the market is Samsung. The fan issue of samsung oven can be resolved using 3 options: 

• Via the thermostat: When the oven is in the heating stage, the thermostat may send voltage to the fan. The high limit thermostat may have an issue sometimes which causes it to send voltage to the oven even after it has cooled. A multimeter can be used to check if the thermostat is at fault. One should check for continuity, a complete path for easy current flow. If the thermostat doesn’t have a clear path for the electricity to flow, it’s better to replace it. 
• Via the control board: According to the sensor boards and user settings, the control board of the oven features relays that help in regulating the power to the broils, brake and fan circuits. However, it is advisable that you check the thermostat before attempting to replace the control board.
• Thermostat- once the oven heats up, the thermostat sends voltage to the oven fan. There may be instances where the thermostat keeps sending the voltage even after the oven has cooled down. This may occur when the thermostat contacts are stuck close. You will then need to check whether your thermostat is at fault by using the multimeter. If the thermostat doesn’t have a clear path for electricity flow, then it needs to be replaced. 

Final Thoughts

The microwave fan is one component that keeps it ventilated perfectly by drawing in air into the exhaust ducts through the microwave vents. This process of drawing air makes sure that all the heat and moisture, any odor or particulate matter present that might have been created during the cooking process, may be eliminated. If you take it upon yourself to repair a faulty vented OTR microwave, you better learn how to remove an over-the-range microwave and put it back up before your reach for your bag of tools.

Taking good care of your appliances should be your priority and it also ensures that you are able to use them for an extended period of time. The main control board of the oven hardly goes bad, so the reason behind the fan not turning off, could in most situations be the thermostat which is prone to failures.