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 sounds. Some noises — like a couple of minor pops or clicks ahead of the warm air beginning to blow — are perfectly harmless. But others could affect the equipment or even endanger 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 suggest the blower wheel has come loose from the motor shaft, or the wheel or motor mount is damaged or failing. No matter what the exact problem, you should power down your furnace if you hear 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 start heating your home. A loud boom at startup likely means the burners are dirty, resulting in delayed ignition. When the gas finally does ignite, you hear this frightening furnace noise.

A small explosion each time your furnace turns on could bust the heat exchanger, an expensive repair that may necessitate you to remove and replace the entire furnace. Don’t let it come to this! Shut off your furnace if you hear a loud boom at startup, and don’t use it again until it has been repaired.

Squealing or Whining Sounds

A screaky or loud squealing furnace noise generally indicates poor lubrication. Like many mechanical equipment with moving parts inside, they need lightweight oil to operate smoothly. If the parts are not lubricated, components grate against each other and cause unwanted wear and tear. Look into having this issue remedied right away to prevent premature furnace failure.

Chirping Noise

The sound of a bird trapped in your furnace certainly warrants investigation. If you notice chirping coming from the furnace upon the first activation of the season, it could merely mean your furnace is warming up after months of no use. In this situation, the sound should stop after a few cycles.

However, if the chirping continues, it could imply the pulley for the blower motor is misaligned or the mounting plate is touching the blower wheel. This isn’t automatically a safety hazard, but the only solution to eliminate the annoying furnace noise is to have a technician conduct a repair.

Screeching Furnace

Screeching noises are an unmistakable warning sign 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 resulting in a much more expensive repair. Insulate yourself from this hassle by changing the worn-out belt sooner rather than later.

Constant Clicking.

Some furnaces give off a fast series of clicks when they turn on and off. There is nothing unusual about that. However, if the noise carries on longer than a minute or so, this could suggest an electrical issue. Don't risk an electrical fire! Simply call a furnace repair professional to fix the problem promptly.

Thwapping Sounds

The blower motor should operate without problems when the furnace switches on. If you notice a thwapping sound that rapidly picks up speed as the blower gets going, this is a strong indication that something is snagged in the fan, and the blades are smacking it with each rotation. A simple repair should be all it takes to eliminate this bothersome furnace noise and reduce the risk of damaging the blower motor.

Rattling Furnace

A few different problems can cause your furnace to rattle. It might be as simple as a loose door cover, so verify that option first. If the rattling continues, the most probable culprit is a failing blower motor. Take this as a warning sign to have your furnace repaired before it breaks down completely.

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 detached, allowing conditioned air to escape. These aren’t urgent matters, but if you have them fixed quickly, you’ll spend less on your heating and cooling bills long term.

Schedule Furnace Repair with Service Experts Heating & Air Conditioning

Are you unsure whether the furnace noises you hear match these descriptions? Maybe nothing’s wrong, but if you want to be 100% sure, the easiest thing to do is to call a professional. At Service Experts Heating & Air Conditioning, we have emergency furnace repair to get your heater functioning properly as fast as possible. Be confident 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 fix it! To find out more or to arrange a furnace repair visit, please get in touch with a Service Experts office near you.

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