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 unfamiliar noises. Some noises — like a few minor pops or clicks prior to the warm air beginning to blow — are completely harmless. But others could ruin the equipment or even jeopardize your health if you neglect them. Among the possible noises that you may hear, here are nine that are worthy of an immediate furnace repair.

Scraping Furnace Noise

When you hear a sound like metal against metal, this could mean the blower wheel has loosened from the motor shaft, or the wheel or motor mount is broke. Regardless of the exact problem, you should shut off your furnace if you hear a scraping sound and call a professional for an urgent repair.

Loud Boom at Startup

When you start your furnace, the burners should ignite immediately and begin heating your home. A loud boom at startup probably means the burners are dirty, producing a delayed ignition. When the gas finally does ignite, you hear this frightening furnace noise.

A small boom each time your furnace turns on could break the heat exchanger, a costly repair that might require you to switch out the entire furnace. Act before it gets to this point! 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 squealing furnace noise typically indicates poor lubrication. Like many mechanical equipment with moving parts inside, they need lightweight oil to operate smoothly. Without this, components rub against each other and cause unnecessary wear and tear. Our recommendation is to have this problem remedied right away to prevent premature furnace failure.

Chirping Noise

The sound of a bird caught in your furnace certainly 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 dissipate after a few cycles.

However, if the chirping doesn’t subside, it could indicate the pulley for the blower motor is crooked or the mounting plate is contacting the blower wheel. This isn’t automatically a safety risk, but the only choice 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 wearing out. If the fraying belt splits, it could whip around inside the furnace, breaking other components and contributing to 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 quick series of clicks when they flip on and off. There is nothing unusual about that. Having said that, if the noise continues longer than a minute or so, this could suggest an electrical complication. 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 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 stuck in the fan, and the blades are striking it with each rotation. A straightforward repair should be all that's required to get rid of this pestering 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 persists, the most plausible reason is a declining 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 loose, allowing conditioned air to release. These aren’t emergency matters, but if you have them fixed quickly, you’ll spend less on your heating and cooling bills over the long haul.

Schedule Furnace Repair with Service Experts Heating & Air Conditioning

Are you undecided whether the furnace noises you hear align with 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 offer emergency furnace repair to get your unit performing properly as soon 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 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.