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 it will likely catch your attention if the equipment starts making odd noises. Some noises — like a couple of small pops or clicks ahead of the warm air beginning to blow — are completely harmless. But others could ruin the equipment or even jeopardize your health if you ignore them. Among the possible noises that you may hear, here are nine that warrant an immediate furnace repair.

Scraping Furnace Noise

When you hear a sound like metal against metal, this could mean the blower wheel has loosened from the motor shaft, or the wheel or motor mount is damaged or failing. No matter the precise problem, you should shut off your furnace if you notice a scraping sound and call a professional for an emergency repair.

Loud Boom at Startup

When you fire up your furnace, the burners should ignite without delay and get started heating your home. A loud boom at startup probably means the burners are dirty, producing a delayed ignition. When the gas at last does ignite, you hear this scary furnace noise.

A small explosion each time your furnace turns on could crack the heat exchanger, a pricey repair that may necessitate you to replace the entire furnace. Act before it gets to this point! Switch off your furnace if you hear a loud boom at startup, and do not activate it again until it has been repaired.

Squealing or Whining Sounds

A high-pitched squealing furnace noise typically indicates poor lubrication. Shaft bearings and other moving parts require lightweight oil to function smoothly. If the parts are not lubricated, components grind against each other and cause unnecessary wear and tear. Our recommendation is to have this situation remedied right away to prevent premature furnace failure.

Chirping Noise

The sound of a bird caught in your furnace absolutely warrants investigation. If you notice chirping coming from the furnace upon the first activation of the season, it could just mean your furnace is warming up after several months of no use. In this situation, the sound should go away after a few cycles.

However, if the chirping does not end, it could imply the pulley for the blower motor is crooked or the mounting plate is contacting the blower wheel. This isn’t automatically a safety hazard, but the only way to stop the irritating furnace noise is to have a technician conduct a repair.

Screeching Furnace

Screeching noises are definite indicators that the fan belt is failing. If the fraying belt breaks, it could whip around inside the furnace, harming other components and resulting in a much more expensive repair. Insulate yourself from this hassle by exchanging the worn-out belt sooner rather than later.

Repeated Clicking.

Some furnaces give off a quick series of clicks when they switch on and off. This is common and no reason to be concerned. That said, if the noise carries on longer than approximately 60 seconds, this could indicate an electrical issue. Don't risk your home catching fire by a faulty electrical situation; call a furnace repair professional to correct the problem immediately.

Thwapping Sounds

The blower motor should function without problems when the furnace turns on. If you discover a thwapping sound that dramatically picks up speed as the blower gets going, this could mean something is snagged in the fan, and the blades are smacking it with each rotation. A quick repair should be all it takes to get rid of this pestering furnace noise and protect against damaging the blower motor.

Rattling Furnace

There are several possible reasons for your furnace to produce a rattling sound. It might be as simple as a loose door cover, so check this first. If the rattling remains, the most probable root cause is a malfunctioning blower motor. Consider this a warning sign to have your furnace repaired before it is an urgent situation.

Whistling or Vibrating

When these noises come from the furnace, it could mean the air intake vent is dislodged. 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 address it promptly, you’ll pay less 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 correspond to these descriptions? Maybe nothing’s wrong, 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 unit performing properly as fast as possible. Rest assured knowing that we stand behind our work with a one-year, 100% satisfaction guarantee. If you’re disappointed 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 speak a Service Experts office near you.

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