9 Common Furnace Noises and What They Mean

If you've had your furnace for several winter seasons, you know how it’s supposed to sound. So it will likely catch your attention if the unit starts making weird noises. Some noises — like several faint pops or clicks before the warm air beginning to blow — are normal and harmless. But others could damage the equipment or even endanger your health if you ignore them. While there are many more furnace noises to consider, here are nine that justify an immediate furnace repair.

Scraping Furnace Noise

The moment you hear a sound like metal scraping on metal, this could mean the blower wheel is becoming detached from the motor shaft, or the wheel or motor mount is broke. No matter the specific problem, you should power down your furnace if you discover 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 right away and start heating your home. A loud boom at startup likely means the burners are dirty, producing a delayed ignition. When the gas at last does ignite, you hear this terrifying furnace noise.

A small blast each time your furnace turns on could crack the heat exchanger, a pricey repair that may force 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 squealing furnace noise typically signifies 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 needless wear and tear. We suggest getting this issue 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 perceive chirping when you fire up the furnace for the first time of the season, it could just mean your furnace is warming up after an extended period of no use. In this case, the sound should dissipate after a few cycles.

However, if the chirping continues, it could mean the pulley for the blower motor is crooked 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 perform a repair.

Screeching Furnace

Screeching noises are an unmistakable warning sign that the fan belt is deteriorating. If the fraying belt cracks, it could spin inside the furnace, harming other components and contributing to a much more expensive repair. Insulate yourself from this hassle by replacing 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 completely normal. However, if the noise carries on longer than approximately 60 seconds, this could indicate an electrical issue. Don't risk an electrical fire! Simply call a furnace repair professional to correct the problem without delay.

Thwapping Sounds

The blower motor should run properly when the furnace turns on. If you notice a thwapping sound that dramatically picks up speed as the blower gets going, this could mean something is stuck in the fan, and the blades are hitting it with each rotation. A quick repair should be all that's required 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 basic as a loose door cover, so start there. If the rattling continues, the most likely culprit 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 release. These aren’t emergency matters, but if you address it promptly, 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? Perhaps nothing is wrong, but for your peace of mind, the best thing to do is to call a professional. At Service Experts Heating & Air Conditioning, we have emergency furnace repair to get your heater performing properly as fast as possible. Feel safe 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 get it corrected! 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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