Microwave - Automatic Fan Feature

Over-the-range microwaves have an automatic fan feature to help protect the electronic components, and also helps the cooking area get rid of excess heat. The built-in thermostat automatically turns the vent fan on if the unit is too hot, and will not turn off until the microwave is cool again. You will not be able to turn the vent fan off manually during this time.  

• "Too hot" means the temperature around the control panel is above 150 degrees F. 
• The fan will shut off when the control surface is less than 150 degrees F.