What’s That Sound? Unusual Furnace Sounds and What to do About Them

Do you get into bed, already falling asleep and are suddenly woken by a loud pop, scrape, or squeal? If you’re wondering what could cause such a stir, it’s probably your furnace. Don’t waste your night trying to search for the sound, instead call Service Champions! Our HVAC techs can diagnose any furnace sounds and fix your system so you can have a quiet night.

Does Your Furnace Make a Scraping Sound?

You know the sound of metal grinding against metal? That’s not a sound you want coming from your furnace, so if you ever hear it, that’s your sign to schedule an HVAC appointment immediately. We can usually attribute a scraping noise to one of two things: either a broken motor mount or a broken blower wheel.

The reason you need to have this unusual furnace sound checked out immediately is because a broken or loose blower wheel can cause major damage to your entire system. A broken motor mount can affect the blower wheel. When the motor mount is damaged, it can’t hold the blower wheel in place.

What About Wheezing?

Do you ever hear a wheezing sound floating around your home? That’s not an asthmatic ghost, it’s your furnace. The wheezing or whooshing sound could potentially be from a dirty air filter. If your air filter is left for too long, it will inevitably get full of dust, dander, and other particles from your indoor air. When the air filter is too full, your furnace needs to push air through the grit. The wheezing noise is treated air pushing through the full air filter.

Sc Furnacesounds 01

Banging, Booming, and Popping

Does your furnace ever make a boom or pop noise when it’s first starting up? Chances are high your furnace burner is dirty. When a furnace burner is clogged with dust, dirt, or other obstacles it causes gas to build up and make a popping noise when the flame finally ignites.

Sc Furnacesounds 02

Another reason for banging, booming or popping is that your metal ducts could be expanding and contracting with the changes in temperature. If your home is equipped with metal ductwork, this is completely normal and nothing to be concerned about.

Are You Hearing a Pinging Noise?

As we mentioned above, your ductwork expands and contracts with temperature changes. A ping, ping, ping noise is just an indicator that your ductwork is doing its job.

What Does it Mean if My Furnace is Whining or Squealing?

If you ever hear an unusual squealing sound coming from your furnace, chances are something is wrong with the blower belt. Either the belt is worn out, misaligned, or in need of lubrication. An HVAC tech can look at this and diagnose it during a routine tune-up.

Sc Furnacesounds 03

And Finally, Why Do I Hear a Crackling?

Crackling noises are almost concerning, but if they’re coming from your furnace, they may be nothing to worry about. If you hear a crackling sound coming after your furnace is off, then it’s completely normal. The ductwork and furnace itself will make crackling noises as it cools down and turns off.

Sc Furnacesounds 04

Hearing Something Strange Coming from Your Furnace?

Don’t wait to schedule an appointment with an expert from Service Champions. We’ve been in the business for over 20 years, so we know what we’re doing. Every one of our HVAC technicians go through thorough training to bring you the best service in Southern California. If you’re in Los Angeles, Orange, or Riverside county, call the number at the top of the screen or click here to book an appointment today.