Skip to Content

Furnace Noises that Should Disturb You

woman surprised

Like almost all dogs (and cats as well), I suffer from a condition called brontophobia. No, it’s not a fear of Brontosauruses—although it does come from the same Greek root word meaning “thunder.” Betcha didn’t expect Ol’ Olive here to be up on her classical language, right? Well, as I like to say, Amicus hominis canis! Which means a dog is a man’s best friend, and I’m sorry but I couldn’t find anything better with an Internet search.

Anyway, the point is brontophobia means “fear of loud noises.” It’s an important defense from danger if you’re a dog or a cat. But it works for you humans as well! And it especially works when it comes to a home furnace. Noises from a furnace you don’t expect to hear are often warnings the heating system isn’t working the way it should and need repairs. So without further ado, here is my list of furnace noises you don’t want to hear!

Noise Primus: Squealing

This mechanical sound is usually something wrong with the blower fan. If you have an older furnace that still uses a fan belt to roatate the blower fan, this noise points to a slipped fan belt that will need to be fixed (or replaced) before the blower stops working. Another possibility is bearings wearing down in the blower fan motor.

Noise Secundus: Rattling

The basic explanation for this is often a loose front panel. You may only need to ensure the panel is screwed down tightly. But if the noises continue, my guess is you have a motor that’s out of alignment. The repair work necessary must come from experienced HVAC technicians.  (I can’t emphasize enough how you must leave furnace repair jobs to licensed experts; a furnace can become unsafe in the wrong hands.)

Noise Tertius: Clicking

When a furnace turns on and off, clicking sounds are normal. But clicking from the units at other times is a warning. One possibility is a damaged relay. A more worrying source is cracks in the heat exchanger of a natural gas furnace, which poses a health risk. Have the problem checked out, no matter what!

Noise Quartus: Grinding

The sound of mechanical grinding is a warning to shut the furnace off right away. Whatever is wrong is causing damage to the system, and you don’t want it to continue and lead to a bigger repair problem. A likely cause is a motor wearing down or trouble with the fan belt. Don’t attempt to use the furnace again until help arrives.

When you need repairs for your furnace in Maryville, TN, our team is the one to call. We’re here to provide fast repair work to keep your family safe and comfortable. If necessary, we’ll replace your furnace with a new unit. (This is often the best route if you have a furnace that’s more than 15 or 20 years old. You receive better safety and much higher energy efficiency.)

Stay warm and safe,

Oliva (My name in Latin!)