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'll likely notice if the equipment starts making odd noises. Some noises — like a few faint pops or clicks ahead of the warm air beginning to blow — are normal and harmless. But others could damage the equipment or even jeopardize your health if you neglect them. Of all the furnace noises you might encounter, here are nine that warrant an immediate furnace repair.

Scraping Furnace Noise

The moment you hear a sound like metal against metal, this could mean the blower wheel is becoming detached from the motor shaft, or the wheel or motor mount has broken. No matter the precise problem, you should shut off your furnace if you discover a scraping sound and call a professional for an critical repair.

Loud Boom at Startup

When you fire up your furnace, the burners should ignite immediately and get started heating your home. A loud boom at startup probably means the burners are dirty, causing a delayed ignition. When the gas eventually does ignite, you hear this scary furnace noise.

A small explosion each time your furnace turns on could bust the heat exchanger, an expensive repair that may force you to remove and replace the entire furnace. Don't wait to act when you hear a noise like that! Turn 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 screaky or loud squealing furnace noise usually signifies poor lubrication. Like many mechanical equipment with moving parts inside, they need lightweight oil to function smoothly. If these parts are dry, components grind against each other and cause unnecessary wear and tear. Our recommendation is to have this situation remedied right away to avoid premature furnace failure.

Chirping Noise

The sound of a bird trapped in your furnace absolutely warrants investigation. If you hear chirping during the first furnace cycle of the season, it could just mean your furnace is warming up after months of no use. In cases like this, the sound should end after a few cycles.

However, if the chirping does not end, it could indicate the pulley for the blower motor is crooked or the mounting plate is contacting the blower wheel. This isn’t always a safety risk, but the only solution to stop the irritating furnace noise is to have a technician perform a repair.

Screeching Furnace

Screeching noises are an unmistakable warning sign that the fan belt is deteriorating. If the fraying belt splits, it could create all kinds of issues inside the furnace, breaking other components and leading to a much more expensive repair. Insulate yourself from this hassle by changing the worn-out belt sooner rather than later.

Repeated Clicking.

Some furnaces give off a fast series of clicks when they turn on and off. This is completely normal. Having said that, if the noise continues longer than a minute or so, this could signal an electrical problem. Don't risk an electrical fire! Simply call a furnace repair professional to correct the problem promptly.

Thwapping Sounds

The blower motor should perform properly when the furnace activates. If you notice a thwapping sound that rapidly picks up speed as the blower gets going, this could mean something is snagged in the fan, and the blades are striking it with each rotation. A simple repair should be all you need to eliminate this bothersome 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 basic as a loose door cover, so verify that option first. If the rattling continues, the most plausible culprit is a declining blower motor. Consider this 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 loose, allowing conditioned air to release. These aren’t emergency matters, but if you have them fixed quickly, you’ll save money on your heating and cooling bills long term.

Schedule Furnace Repair with Service Experts Heating & Air Conditioning

Are you uncertain 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 system back up and running 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 fix it! For additional information or to arrange a furnace repair visit, please get in touch with a Service Experts office near you.

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