Why Is Your Furnace Making Weird Noises?

You rely on your furnace to properly heat your home and keep it comfortable. Unfortunately, however, even the best furnaces can't last forever and will often run into problems along the way.

The good news is that furnaces are great about sending out warning signs that something is amiss. One such warning sign is odd noises coming from your furnace.

If you're experiencing strange furnace sounds, don't ignore them. More often than not, they indicate that a problem is brewing. And, if you let that problem go, it could ultimately cause major damage to your furnace, which could leave you having to replace it entirely instead of just submitting to a simple repair job.

Loud Operation

Sometimes, you may simply notice that your furnace sounds louder than usual. Most furnaces make a gentle noise when they turn on and when they're running. But, if your furnace is suddenly super loud when turning on or operating, that's not normal.

More often than not, damaged fans or fan bearings are the cause of this issue. Thankfully, it's a simple fix, but you'll still need to have a furnace repair technician diagnose the issue and come up with a repair plan.

Big Bangs

Hearing your furnace let out a big banging noise can be scary. This sound, in fact, is often mistaken for gunshots or fireworks.

However, this loud noise is more commonly attributed to gas build-up within your furnace, which can be very dangerous for both your home and your furnace. Furthermore, that bang you heard could have damaged the heat exchanger, which could lead to even more problems.

For best results and increased safety, turn the furnace off and don't operate it again until after a professional has taken a look.

Scraping Sounds

Another thing to listen for is any kind of scraping or screeching noise coming from your furnace.

This sound, which can be very unpleasant, usually indicates that your blower is damaged and will need to be professionally replaced.


Finally, if your furnace starts whistling, don't sing along.

A whistling furnace often has gaps in its ducts or even an entire hole or opening where one shouldn't be.

While you can search for this gap yourself, it's really better to let a pro handle the job, especially since one gap can often lead to others without proper repair.

Your furnace should never be noisy when it's working properly. So, if you hear these sounds or any others, always take it as a clue that something not quite right is going on.