If your fan limit switch is set to AUTO but the fan continues to run without ever stopping, you’ll need to call a professional. Two problems that could cause your fan to run without stopping include: A bad fan limit switch that needs to be replaced. Bad thermostat wiring.
Is it OK to run furnace fan constantly?
Running your furnace fan all the time isn’t exactly a bad thing. In fact, there’s no need to worry about the fan wearing out or breaking down because it’s designed to run continuously, and there’s an array of benefits connected to this. Here are some of them: Better circulation of heated and cooled air.
Why does my furnace fan not shut off?
The way to fix this is to change the setting on your thermostat fan switch to “AUTO”. In this setting, the furnace fan will only come on after the furnace has warmed up a little, and it will shut off again after the furnace cools down a minute or two after a heating cycle.
What causes a fan to keep running?
The reason fans keep running after an engine is shut down is for the cooldown of the radiator. A replacement sensor for the electric cooling fan is likely to need to be replaced as it controls the fan.
Why is my fan running when my thermostat is off?
If the fan is the only thing running when the AC unit isn’t, there may be a faulty relay switch prohibiting the settings on the thermostat from being communicated to the fan. Another cause could be a wiring issue or a short circuit preventing the system from recognizing the on and off signals.
Why does my furnace fan keep turning on and off?
If your blower is constantly turning on/off when the furnace isn’t heating… …you most likely have a bad fan limit switch. Your furnace fan limit switch is basically a control system that determines when the furnace blower assembly should turn on and off.
How much does a fan limit switch cost?
$4 to $25
Average Cost of a New Furnace Limit Switch
You will need to buy a high limit switch that is produced by the same manufacturer as your furnace unit. Depending on who your OEM is, this component could roughly cost you anywhere from $4 to $25.
Where is furnace fan limit switch?
Your fan limit switch can be found right under the furnace hood. Have a close look at it. You should see a little white button/knob, this is your fan limit switch. If that white button appears to be pushed in, the switch has been set to manual override, which means the fan will run constantly.
