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 system starts making weird noises. Some noises — like a couple of minor pops or clicks before the warm air beginning to blow — are normal and harmless. But others could ruin the equipment or even threaten 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

If you hear a sound like metal against metal, this could indicate the blower wheel has loosened from the motor shaft, or the wheel or motor mount is broke. No matter what the precise problem, you should shut off your furnace if you notice a scraping sound and call a professional for an critical repair.

Loud Boom at Startup

When you start your furnace, the burners should ignite without delay and start heating your home. A loud boom at startup potentially means the burners are dirty, resulting in delayed ignition. When the gas at last does ignite, you hear this shocking furnace noise.

A small explosion each time your furnace turns on could break the heat exchanger, an expensive repair that may necessitate you to remove and replace the entire furnace. Don't wait to act when you hear a noise like that! Shut 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. Multiple parts of a furnace need lightweight oil to operate smoothly. If these parts are dry, components grind against each other and cause unwanted wear and tear. Our recommendation is to have this issue 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 merely mean your furnace is warming up after several months of no use. In cases like this, the sound should stop after a few cycles.

However, if the chirping does not end, it could imply the pulley for the blower motor is crooked or the mounting plate is touching the blower wheel. This isn’t necessarily a safety hazard, but the only solution to get rid of 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 wearing out. If the fraying belt cracks, it could create all kinds of issues inside the furnace, breaking other components and leading to a much more expensive repair. You can protect yourself from this unexpected expense by changing the worn-out belt sooner rather than later.

Continual Clicking.

Some furnaces give off a rapid series of clicks when they switch on and off. This is completely normal. Having said that, if the noise lasts longer than approximately 60 seconds, this could suggest an electrical complication. Don't risk an electrical fire! Simply call a furnace repair professional to correct the problem promptly.

Thwapping Sounds

The blower motor should function smoothly when the furnace activates. If you notice a thwapping sound that dramatically picks up speed as the blower gets going, this likely means something is caught in the fan, and the blades are smacking it with each rotation. A quick repair should be all it takes to get rid of this annoying 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 simple as a loose door cover, so verify that option first. If the rattling continues, the most probable culprit is a malfunctioning blower motor. Consider this a warning sign to have your furnace repaired before it entirely fails.

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 loose, allowing conditioned air to release. These aren’t critical matters, but if you have them fixed quickly, 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? Maybe nothing’s 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 provide emergency furnace repair to get your unit back up and running as quickly 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 fix it! To find out more or to arrange a furnace repair visit, please speak a Service Experts office near you.