9 Common Furnace Noises and What They Mean

Over time, when you fire up your furnace, you know how it’s supposed to sound. So you'll likely notice if the system starts making odd sounds. Some noises — like a couple of faint pops or clicks before the warm air beginning to blow — are perfectly harmless. But others could damage the equipment or even threaten your health if you ignore them. Of all the furnace noises you might encounter, here are nine that justify an immediate furnace repair.

Scraping Furnace Noise

When you hear a sound like metal scraping on metal, this could indicate the blower wheel has come loose from the motor shaft, or the wheel or motor mount is damaged or failing. No matter 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 quickly and start heating your home. A loud boom at startup potentially means the burners are dirty, resulting in delayed ignition. When the gas eventually does ignite, you hear this scary furnace noise.

A small boom each time your furnace turns on could crack the heat exchanger, a pricey repair that may necessitate 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 don’t use it again until it has been repaired.

Squealing or Whining Sounds

A high-pitched squealing furnace noise usually signifies poor lubrication. Shaft bearings and other moving parts require lightweight oil to function smoothly. Without this, components rub against each other and cause unnecessary wear and tear. Look into having this issue remedied right away to avoid premature furnace failure.

Chirping Noise

The sound of a bird caught in your furnace absolutely warrants investigation. If you perceive chirping coming from the furnace upon the first activation of the season, it could just mean your furnace is warming up after months of no use. In this situation, the sound should end after a few cycles.

However, if the chirping doesn’t subside, it could imply the pulley for the blower motor is misaligned or the mounting plate is contacting the blower wheel. This isn’t always a safety threat, but the only option to stop the annoying furnace noise is to have a technician perform a repair.

Screeching Furnace

Screeching noises are definite indicators that the fan belt is wearing out. 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 exchanging the worn-out belt sooner rather than later.

Repeated Clicking.

Some furnaces give off a rapid series of clicks when they flip on and off. There is nothing unusual about that. Having said that, if the noise carries on longer than about one minute, this could suggest an electrical problem. Don't risk your home catching fire by a faulty electrical situation; call a furnace repair professional to correct the problem promptly.

Thwapping Sounds

The blower motor should operate properly when the furnace activates. If you notice a thwapping sound that quickly picks up speed as the blower gets going, this likely means something is caught in the fan, and the blades are striking it with each rotation. A quick repair should be all that's required to get rid of this pestering furnace noise and prevent damaging the blower motor.

Rattling Furnace

There are several possible reasons for your furnace to produce a rattling sound. It might be as simple as a loose door cover, so verify that option first. If the rattling persists, the most likely reason is a malfunctioning blower motor. Take this as a warning sign to have your furnace repaired before it breaks down completely.

Whistling or Vibrating

When your furnace has an air intake vent issue, you will often hear a whistling or humming vibration sound. If the whistling or vibrating comes from a vent, your ductwork is likely separated somewhere, allowing conditioned air to release. These aren’t urgent matters, but if you fix it soon, you’ll pay 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 correspond to 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 have emergency furnace repair to get your heater performing properly as quickly 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.

chat now widget box