Why Is My Furnace Making Strange Sounds?

What Are Those Strange Sounds from Your Furnace?

Have you ever woken up in the middle of the night only to hear a scary scraping noise or an unexplained bump in the night? Though some people think the noises are from ghosts or burglars, we’re here to tell you that they could actually be coming from your furnace.

When you’re startled awake by a strange sound, first check to make sure everything is ok. Then, take a moment to listen to the noise and if you can, make note of it. When the sun is up and businesses are open, schedule an appointment with an HVAC professional to figure out why your furnace is making sounds.

Furnace Making a Squealing Noise

There are times when you may hear a high pitched squealing or squeaking coming from your furnace. Yes, this noise is very annoying and yes, it’s a sign of trouble.

The most obvious culprit is the belt in your blower motor. Just like a car, your furnace has a belt that helps power the system. With enough use the belt can wear thin and need to be replaced. When the belt worn too thin or out of alignment it will make a high pitched squealing noise.

The fun doesn’t stop there, when pieces of the blower motor are out of place, they can make a very loud squealing or squeaking noise. You can usually blame this on loose parts scraping against each other.

There are a few reasons beyond the bely why your furnace may start squealing. A good place to look is the motor and blower motor. The motor is held in place by ball bearings. Sometimes those bearings can come loose or start to wear out, which will lead to the noise.

When your furnace makes a strange sound, have a professional check your blower motor.

Furnace Making a Clicking Noise

We’ve also heard our San Diego homeowners talk about a clicking noise that comes from their furnace. Fortunately, this is something we’re used to dealing with.

One reason your furnace may start to click is because there’s a problem with the ignition. The clicking noise comes from the furnace trying to start.

Sometimes those ball bearings we mentioned above can do more than squeal. They can also click. Another reason for that persistent clicking, something could be getting in the fan spokes. This would make the fan click every time it makes a rotation.

Now that you know your furnace is clicking, perhaps the better question is why. There are a few answers. One is that with time things just wear out and need to be fixed. Or something could have been knocked out of alignment. We are in earthquake country after all.

Strange sounds can come from anywhere in the furnace.

No matter what it is, a clicking noise should not be ignored. Take the time and schedule an appointment with your local HVAC company to have it checked out.

Furnace Making a Rattling Noise

Like most things in this world, a furnace needs balance to perform well. When things are not aligned, it’s safe to say they won’t work too well.

An example of this is the blower motor. In addition to the ball bearings, this part usually has balancing weights of clips attached to it.

The issue is that sometimes these weights can be thrown out of balance. This can happen when too much dust and debris get in between the weights and the motor. When the weights are out of alignment, the blower motor can sound like a giant rattle.

Another reason you may hear rattling coming from your furnace is that a screw came loose or there’s some stray scrap metal bouncing around in your system.

And the final major reason for a rattling noise is ducts. Over time, ductwork can pry itself loose and needs to be reattached. The rattling comes from ductwork that has fallen out of place.

Safe to say, no matter what the noise is, you need to call an HVAC expert when you hear anything funky coming from your vents.

To have something checked out or to simply learn more about your system, schedule an appointment with the experts at ASI, The While Glove Guys.