Furnace Runs Constantly

April 17, 2018


Here are 4 common reasons your furnace is running constantly.

hands in front of an air vent

If you have noticed that your furnace is constantly running, even as the cold weather is starting to ease up, it might be a sign that something’s lurking in your heating system. A heating system works by distributing warm around your home. If you hear the fan running constantly, you might start to wonder why. Here are 4 common reasons your furnace is running constantly.

Incorrect Setting of Your Thermostat Temperature

If you don’t have your thermostat set to the correct temperature, it can have your furnace running overtime. During the colder months, you will want the thermostat to be turned to “heat.” If you want to check that the furnace is working, you can turn the thermostat lower than the temperature of the room. If the heater is working correctly, then the fan should shut off when you turn the temperature down. If you have your thermostat set too high, you might be setting the temperature higher than your system can keep up with.

Not Having the Right Fan Setting

On most thermostats, you can set your fan either to “on” or “auto.” There are also some thermostats that will allow you to adjust the fan’s speed. If you are constantly hearing the heat going on, then try setting the fan to “auto” so that it isn’t running even when it doesn’t need to. The unit should know when the fan needs to circulate, so let it do its job instead of setting the fan to “on.”

Problems With the Limit Switch

If it isn’t an issue with the fan or the temperature setting, then there is the possibility that it might be a problem with the limit switch. Your equipment has a limit switch that tells the fan when it is time to turn on or off, and it is usually located under the hood of your furnace. Once you find it, you will want to check to see if it is switched to “manual override” or to “auto.” If it is switched to “manual override,” then you will want to switch it to “auto” and let it run when the furnace indicates it is time instead of it always being on.

You Didn’t Weatherize

If you have a lot of leaks and drafts in your home, then it might be time to consider weatherizing your home to keep the warm in and the cold out – or vice-versa. Your furnace might be working overtime simply because all the heat is escaping out through the doors and windows. If it isn’t a problem with the furnace, then you might want to consider calling an insulation expert.

Having Problems With Your Furnace Running Constantly?

Give Scott-Lee Heating a call 24/7 at (314) 756-9444.  We have been serving the greater St. Louis metropolitan area for over 35 years and are dedicated to providing you with the highest quality and most energy efficient heating, air conditioning and geothermal systems available.