9 Common Furnace Noises and What They Mean

After a few years of running your furnace every winter, you know how it’s supposed to sound. So it will likely catch your attention if the equipment starts making weird sounds. Some noises — like a few small pops or clicks before the warm air beginning to blow — are completely harmless. But others could damage the equipment or even threaten your health if you neglect them. Of all the furnace noises you might encounter, here are nine that are worthy of an immediate furnace repair.

Scraping Furnace Noise

If you hear a sound like metal scraping on metal, this could mean the blower wheel has come loose from the motor shaft, or the wheel or motor mount has broken. No matter what the specific problem, you should turn off your furnace if you discover a scraping sound and call a professional for an critical repair.

Loud Boom at Startup

When you fire up your furnace, the burners should ignite quickly and begin heating your home. A loud boom at startup likely means the burners are dirty, producing a delayed ignition. When the gas eventually does ignite, you hear this shocking furnace noise.

A small blast each time your furnace turns on could crack the heat exchanger, an expensive repair that may force you to 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 screaky or loud squealing furnace noise generally signifies poor lubrication. Shaft bearings and other moving parts require lightweight oil to operate smoothly. If these parts are dry, components grate against each other and cause needless wear and tear. Look into having this situation remedied right away to avoid premature furnace failure.

Chirping Noise

The sound of a bird lodged in your furnace definitely warrants investigation. If you notice chirping during the first furnace cycle of the season, it could merely mean your furnace is warming up after an extended period of no use. In cases like this, the sound should end after a few cycles.

However, if the chirping doesn’t subside, it could indicate the pulley for the blower motor is out of alignment or the mounting plate is contacting the blower wheel. This isn’t necessarily a safety threat, but the only option to eliminate the irritating furnace noise is to have a technician perform 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 whip around inside the furnace, breaking other components and resulting in a much more expensive repair. You can protect yourself from this unexpected expense by replacing the worn-out belt sooner rather than later.

Continual Clicking.

Some furnaces give off a quick series of clicks when they turn on and off. This is common and no reason to be concerned. However, if the noise continues longer than about one minute, this could signal an electrical problem. Don't risk your home catching fire by a faulty electrical situation; call a furnace repair professional to fix the problem promptly.

Thwapping Sounds

The blower motor should operate properly when the furnace activates. If you discover a thwapping sound that dramatically picks up speed as the blower gets going, this could mean something is snagged in the fan, and the blades are striking it with each rotation. A quick repair should be all it takes to eliminate this annoying furnace noise and protect against damaging the blower motor.

Rattling Furnace

A rattling furnace can be caused by multiple issues. It might be as easy as a loose door cover, so check this first. If the rattling persists, the most likely culprit is a malfunctioning blower motor. Take this as a warning sign to have your furnace repaired before it breaks down completely.

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 leak. These aren’t critical matters, but if you fix it soon, you’ll save money on your heating and cooling bills in the long run.

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 offer emergency furnace repair to get your system performing properly as soon as possible. Rest assured 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 set things right! To find out more or to arrange a furnace repair visit, please get in touch with a Service Experts office near you.