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 you'll likely notice if the equipment starts making weird noises. Some noises — like a few small pops or clicks ahead of the warm air beginning to blow — are completely harmless. But others could affect the equipment or even jeopardize your health if you dismiss 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 rubbing on metal, this could suggest the blower wheel is becoming detached from the motor shaft, or the wheel or motor mount is broke. 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 start your furnace, the burners should ignite immediately and begin heating your home. A loud boom at startup likely 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 bust the heat exchanger, a pricey repair that might require you to switch out the entire furnace. Don’t let it come to this! 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 generally signifies poor lubrication. Like many mechanical equipment with moving parts inside, they need lightweight oil to function smoothly. If the parts are not lubricated, components rub against each other and cause needless wear and tear. We suggest getting this situation remedied right away to avoid premature furnace failure.

Chirping Noise

The sound of a bird trapped in your furnace absolutely warrants investigation. If you notice chirping when you fire up the furnace for the first time of the season, it could merely mean your furnace is warming up after an extended period of no use. In this situation, the sound should stop 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 coming in contact with the blower wheel. This isn’t always a safety hazard, but the only solution to eliminate the irritating furnace noise is to have a technician perform a repair.

Screeching Furnace

Screeching noises are an unmistakable warning sign that the fan belt is deteriorating. If the fraying belt splits, it could whip around inside the furnace, harming other components and contributing to a much more expensive repair. Avoid this hassle and cost by changing the worn-out belt sooner rather than later.

Persistent 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 persists 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 without problems when the furnace switches on. If you notice a thwapping sound that dramatically picks up speed as the blower gets going, this is a strong indication that something is snagged in the fan, and the blades are smacking it with each rotation. A simple repair should be all you need to eliminate this annoying furnace noise and prevent damaging the blower motor.

Rattling Furnace

A few different problems can cause your furnace to rattle. It might be as easy as a loose door cover, so check this first. If the rattling persists, the most plausible reason is a declining 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 detached, allowing conditioned air to escape. These aren’t emergency matters, but if you have them fixed quickly, you’ll spend less on your heating and cooling bills in the long run.

Schedule Furnace Repair with Service Experts Heating & Air Conditioning

Are you undecided whether the furnace noises you hear match these descriptions? Maybe nothing’s wrong, but for your peace of mind, the best thing to do is to call a professional. At Service Experts Heating & Air Conditioning, we provide emergency furnace repair to get your unit 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 disappointed with our work anytime in the next 12 months, we’ll set things right! For additional information or to arrange a furnace repair visit, please contact a Service Experts office near you.