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 equipment starts making unfamiliar sounds. Some noises — like several minor pops or clicks ahead of the warm air beginning to blow — are normal and harmless. But others could damage the equipment or even threaten your health if you ignore them. While there are many more furnace noises to consider, here are nine that are worthy of an immediate furnace repair.

Scraping Furnace Noise

The moment you hear a sound like metal scraping on metal, this could suggest the blower wheel is becoming detached from the motor shaft, or the wheel or motor mount is broke. Regardless of the exact 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 start your furnace, the burners should ignite without delay and start heating your home. A loud boom at startup likely means the burners are dirty, causing 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 bust the heat exchanger, a costly repair that might require you to remove and replace the entire furnace. Act before it gets to this point! Shut 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 generally indicates poor lubrication. Shaft bearings and other moving parts require lightweight oil to operate smoothly. Without this, components grate 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 certainly warrants investigation. If you perceive chirping during the first furnace cycle of the season, it could simply mean your furnace is warming up after several months of no use. In this case, the sound should stop after a few cycles.

However, if the chirping doesn’t subside, it could indicate 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 get rid of the annoying furnace noise is to have a technician conduct a repair.

Screeching Furnace

Screeching noises are definite indicators that the fan belt is deteriorating. If the fraying belt splits, it could spin inside the furnace, breaking other components and resulting in 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 fast series of clicks when they turn on and off. This is completely normal. Having said that, if the noise continues longer than about one minute, this could suggest an electrical issue. Don't risk your home catching fire by a faulty electrical situation; call a furnace repair professional to correct the problem without delay.

Thwapping Sounds

The blower motor should operate properly when the furnace activates. If you hear a thwapping sound that dramatically picks up speed as the blower gets going, this is a strong indication that something is caught in the fan, and the blades are smacking 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

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 persists, the most probable culprit is a malfunctioning blower motor. Consider this a warning sign to have your furnace repaired before it entirely fails.

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 escape. These aren’t critical matters, but if you fix it soon, you’ll spend less 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 match these descriptions? Perhaps nothing is 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 provide emergency furnace repair to get your system back up and running as quickly 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! For more information or to arrange a furnace repair visit, please speak a Service Experts office near you.

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