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 might be caught off guard if the unit starts making strange sounds. Some noises — like a few faint pops or clicks before the warm air beginning to blow — are perfectly harmless. But others could impair the equipment or even jeopardize your health if you neglect them. While there are many more furnace noises to consider, here are nine that justify an immediate furnace repair.

Scraping Furnace Noise

When you hear a sound like metal against metal, this could mean the blower wheel is becoming detached from the motor shaft, or the wheel or motor mount is broke. No matter the precise problem, you should power down your furnace if you discover a scraping sound and call a professional for an critical repair.

Loud Boom at Startup

When you start your furnace, the burners should ignite immediately and get started heating your home. A loud boom at startup potentially means the burners are dirty, causing a delayed ignition. When the gas finally does ignite, you hear this terrifying furnace noise.

A small explosion each time your furnace turns on could break the heat exchanger, a costly repair that may force you to remove and replace the entire furnace. Don’t let it come to this! Switch 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 usually implies poor lubrication. Like many mechanical equipment with moving parts inside, they need lightweight oil to function smoothly. Without this, components grind against each other and cause unnecessary wear and tear. Our recommendation is to have this situation remedied right away to protect against premature furnace failure.

Chirping Noise

The sound of a bird trapped in your furnace absolutely warrants investigation. If you hear chirping during the first furnace cycle of the season, it could merely mean your furnace is warming up after several months of no use. In cases like this, the sound should end after a few cycles.

However, if the chirping does not end, it could indicate the pulley for the blower motor is misaligned or the mounting plate is contacting the blower wheel. This isn’t always a safety hazard, but the only way 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 failing. If the fraying belt cracks, it could whip around inside the furnace, damaging other components and resulting in a much more expensive repair. Insulate yourself from this hassle by changing the worn-out belt sooner rather than later.

Persistent Clicking.

Some furnaces give off a rapid series of clicks when they turn on and off. This is common and no reason to be concerned. Having said that, if the noise lasts longer than approximately 60 seconds, this could signal an electrical complication. To avoid risking a house fire, call a furnace repair professional to correct the problem immediately.

Thwapping Sounds

The blower motor should run properly when the furnace switches on. If you hear a thwapping sound that rapidly picks up speed as the blower gets going, this could mean something is stuck in the fan, and the blades are striking it with each rotation. A simple repair should be all it takes to eliminate this annoying furnace noise and reduce the risk of damaging the blower motor.

Rattling Furnace

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

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 detached, allowing conditioned air to leak. These aren’t critical matters, but if you have them fixed quickly, you’ll save money 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 correspond to these descriptions? It might be nothing, but for your peace of mind, the best thing to do is to call a professional. At Service Experts Heating & Air Conditioning, we offer emergency furnace repair to get your unit functioning properly as fast 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 contact a Service Experts office near you.