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 you'll likely notice if the system starts making strange sounds. Some noises — like several minor pops or clicks before 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 justify an immediate furnace repair.

Scraping Furnace Noise

If you hear a sound like metal against metal, this could indicate the blower wheel has come loose from the motor shaft, or the wheel or motor mount is broke. Regardless of the specific 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 right away and begin heating your home. A loud boom at startup potentially means the burners are dirty, which causes 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 break the heat exchanger, a pricey repair that may force you to remove and replace the entire furnace. Don’t let it come to this! 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 squealing furnace noise generally implies poor lubrication. Shaft bearings and other moving parts require lightweight oil to operate smoothly. Without this, components grind against each other and cause unnecessary wear and tear. Look into having this problem remedied right away to protect against premature furnace failure.

Chirping Noise

The sound of a bird entrapped in your furnace absolutely warrants investigation. If you notice chirping during the first furnace cycle of the season, it could simply mean your furnace is warming up after an extended period of no use. In this case, the sound should go away after a few cycles.

However, if the chirping doesn’t subside, it could mean the pulley for the blower motor is out of alignment or the mounting plate is touching the blower wheel. This isn’t necessarily a safety risk, but the only option to stop the irritating furnace noise is to have a technician conduct a repair.

Screeching Furnace

Screeching noises are clear and certain signs that the fan belt is wearing out. If the fraying belt cracks, it could create all kinds of issues inside the furnace, damaging 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.

Constant Clicking.

Some furnaces give off a rapid series of clicks when they turn on and off. There is nothing unusual about that. Having said that, if the noise lasts longer than about one minute, this could suggest an electrical problem. To avoid risking a house fire, call a furnace repair professional to solve the problem immediately.

Thwapping Sounds

The blower motor should run properly when the furnace activates. If you hear a thwapping sound that quickly picks up speed as the blower gets going, this likely means something is snagged in the fan, and the blades are smacking it with each rotation. A simple repair should be all that's required to stop this annoying furnace noise and prevent damaging the blower motor.

Rattling Furnace

A rattling furnace can be caused by multiple issues. It might be as simple as a loose door cover, so check this first. If the rattling remains, the most plausible culprit is a malfunctioning blower motor. Treat this as 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 loose, allowing conditioned air to escape. These aren’t critical matters, but if you fix it soon, you’ll save money on your heating and cooling bills over the long haul.

Schedule Furnace Repair with Service Experts Heating & Air Conditioning

Are you unsure whether the furnace noises you hear align with 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 provide emergency furnace repair to get your system functioning properly as soon 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 speak a Service Experts office near you.

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