Why Won’t My Furnace STOP Running? - H.A. Sun Heating & Air Conditioning, Inc. - Metro Detroit HVAC Skip to content
24/7 Emergency Service Available
(248) 335-4555

Why Won’t My Furnace STOP Running?

We know you’d rather have a furnace that never turns OFF than a furnace that never turns ON … but it’s still a troubling issue. What do you do?

Easy solutions

There are a few potential fixes that don’t require the help of a professional from H.A. Sun. Why? Because, if the furnace not turning off is the result of a little “oopsy daisy” on your end, you can fix it yourself easily. Everybody makes mistakes!

Thermostat fan set incorrectly

Did you know that if your thermostat fan is set to ON, not AUTO, the furnace blower will run constantly? Because you’re telling it to! AUTO means that the blower motor will only run when it has heated air to push into your home. ON means it will run 24/7, even when it doesn’t have hot air to circulate!

Dirty air filter

Did you know that your air filter gets dirty faster in winter than it does in summer? Why is that? It’s because your furnace has to work pretty hard to keep your house warm, meaning that even more air gets circulated through the air filter in winter than in summer. And the more air gets pushed through the filter every day, the more dust and debris gets caught in the filter. You may have heard that you should even change your air filter EVERY month in the wintertime. You probably won’t need to change it every month, but at least CHECK it every month. Why does a dirty air filter prevent your furnace from turning off? Because it’s harder for air to make its way through a dirty filter, meaning your furnace can’t do its job properly, and will never turn off, or will take longer to turn off. So, change that filter!

Difficult solutions

If you’ve checked both of these issues and neither one of them is the problem, then unfortunately the reason your furnace won’t turn off is probably a broken part. We mentioned that leaving the thermostat set to ON is a mistake, but a scenario that’s just as likely is that someone’s furnace blower or thermostat are broken. Or, rather than having a problem with a dirty filter, what if you have a problem with leaky air ducts, making your furnace work harder to try and make up for the lost hot air? These issues require the help of a professional from H.A. Sun to fix!

Call a furnace repair pro

But, that is exactly what we’re here for this holiday season: to fix your furnace. Let one of our experts troubleshoot the issue for you, and help you keep your energy costs down this winter. Just give us a call at (248) 335-4555 or contact us online!