How does a fan limit switch work?


A fan limit switch on your furnace is a vital part of the controls, as it controls what happens if there are any malfunctions within the furnace. It will turn off the burners if it detects a malfunction. Not only that, but it controls when the blowers operated as well. How it essentially works is by turning the blower on and off by regulating the air temperature within in the air chamber. You can adjust the dial to preset temperatures that determine when the fan turns on and off. Once the thermostat reaches that present temperature, the burners will turn off, but the fan will continue to run until the air chamber cools down, at which point it will switch the dial off.
2 Additional Answers Answer for: how does a fan limit switch work
How Does a Fan Limit Switch Work?
The fan limit switch on a furnace is vital not only because it controls when the furnace's blowers operate, but also because it can turn off the burners in case of a malfunction elsewhere in the furnace.... More »
Difficulty: Easy
The fan limit switch works by being a safety control switch. It is located on the furnace right below the plenum. The burner is shut off if it gets too hot. You can find more information at
Explore this Topic
A limit switch works by disengaging a motor when it reaches a certain limit. Kind of like the way a motor in a car's power window works. You can find more information ...
About -  Privacy -  Careers -  Ask Blog -  Mobile -  Help -  Feedback  -  Sitemap  © 2014