9 Common Furnace Noises and What They Mean

After a few years of running your furnace every winter, you know how it’s supposed to sound. So you might be caught off guard if the equipment starts making unfamiliar sounds. Some noises — like a couple of small pops or clicks before the warm air beginning to blow — are perfectly harmless. But others could impair the equipment or even threaten your health if you dismiss them. Of all the furnace noises you might encounter, here are nine that warrant an immediate furnace repair.

Scraping Furnace Noise

When you hear a sound like metal against metal, this could indicate the blower wheel has loosened from the motor shaft, or the wheel or motor mount is damaged or failing. Regardless of the exact problem, you should shut off your furnace if you discover a scraping sound and call a professional for an urgent repair.

Loud Boom at Startup

When your furnace starts up, the burners should ignite right away and begin heating your home. A loud boom at startup likely means the burners are dirty, producing a delayed ignition. When the gas finally does ignite, you hear this frightening furnace noise.

A small blast each time your furnace turns on could crack the heat exchanger, an expensive repair that may necessitate you to remove and replace the entire furnace. Don't wait to act when you hear a noise like that! Shut off your furnace if you hear a loud boom at startup, and avoid using it again until it has been repaired.

Squealing or Whining Sounds

A high-pitched squealing furnace noise generally implies poor lubrication. Like many mechanical equipment with moving parts inside, they need lightweight oil to run smoothly. If the parts are not lubricated, components grind against each other and cause needless wear and tear. Our recommendation is to have this situation remedied right away to protect against premature furnace failure.

Chirping Noise

The sound of a bird lodged in your furnace absolutely warrants investigation. If you hear chirping coming from the furnace upon the first activation of the season, it could simply mean your furnace is warming up after an extended period of no use. In this case, the sound should end after a few cycles.

However, if the chirping does not end, it could imply the pulley for the blower motor is misaligned or the mounting plate is touching the blower wheel. This isn’t always a safety risk, but the only option to stop the annoying furnace noise is to have a technician perform a repair.

Screeching Furnace

Screeching noises are clear and certain signs that the fan belt is failing. If the fraying belt cracks, it could create all kinds of issues inside the furnace, harming other components and contributing to a much more expensive repair. Avoid this hassle and cost by changing the worn-out belt sooner rather than later.

Repeated Clicking.

Some furnaces give off a fast series of clicks when they flip on and off. There is nothing unusual about that. However, if the noise persists longer than approximately 60 seconds, this could suggest an electrical complication. Don't risk an electrical fire! Simply call a furnace repair professional to fix the problem immediately.

Thwapping Sounds

The blower motor should run without problems when the furnace turns on. If you hear a thwapping sound that dramatically picks up speed as the blower gets going, this could mean something is caught in the fan, and the blades are striking it with each rotation. A simple repair should be all it takes to stop this bothersome furnace noise and reduce the risk of damaging the blower motor.

Rattling Furnace

A rattling furnace can be caused by multiple issues. It might be as basic as a loose door cover, so verify that option first. If the rattling continues, the most probable root cause is a declining blower motor. Take this as a warning sign to have your furnace repaired before it is an urgent situation.

Whistling or Vibrating

Noises such as a teapot whistle or the hum of a vibrating item are signals of a problem with the air intake vent. If the whistling or vibrating comes from a vent, your ductwork is likely separated somewhere, allowing conditioned air to leak. These aren’t critical matters, but if you have them fixed quickly, you’ll save money on your heating and cooling bills in the long run.

Schedule Furnace Repair with Service Experts Heating & Air Conditioning

Are you undecided whether the furnace noises you hear match these descriptions? It might be nothing, but the only way to know for sure is to call a professional. At Service Experts Heating & Air Conditioning, we offer emergency furnace repair to get your heater back up and running as quickly as possible. Rest assured knowing that we stand behind our work with a one-year, 100% satisfaction guarantee. If you’re dissatisfied with our work anytime in the next 12 months, we’ll set things right! For more information or to arrange a furnace repair visit, please contact a Service Experts office near you.

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