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 unit starts making unfamiliar sounds. Some noises — like a few minor pops or clicks ahead of the warm air beginning to blow — are perfectly harmless. But others could damage the equipment or even threaten your health if you neglect them. Among the possible noises that you may hear, here are nine that warrant an immediate furnace repair.
Scraping Furnace Noise
When you hear a sound like metal scraping on metal, this could suggest the blower wheel has come loose from the motor shaft, or the wheel or motor mount is broke. No matter what the specific problem, you should switch off your furnace if you hear a scraping sound and call a professional for an emergency repair.
Loud Boom at Startup
When your furnace starts up, the burners should ignite without delay and start heating your home. A loud boom at startup probably means the burners are dirty, causing a delayed ignition. When the gas eventually does ignite, you hear this terrifying furnace noise.
A small boom each time your furnace turns on could bust the heat exchanger, an expensive repair that may force you to 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 typically implies poor lubrication. Like many mechanical equipment with moving parts inside, they need lightweight oil to function smoothly. If these parts are dry, 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.
The sound of a bird entrapped 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 several months of no use. In this situation, 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 automatically a safety risk, but the only way to eliminate the irritating furnace noise is to have a technician conduct a repair.
Screeching noises are clear and certain signs that the fan belt is failing. If the fraying belt breaks, 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.
Some furnaces give off a fast series of clicks when they flip on and off. There is nothing unusual about that. However, if the noise continues longer than about one minute, this could indicate an electrical issue. To avoid risking a house fire, call a furnace repair professional to fix the problem immediately.
The blower motor should perform without problems when the furnace switches on. If you discover a thwapping sound that quickly 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 simple repair should be all you need to eliminate this bothersome furnace noise and prevent damaging the blower motor.
There are several possible reasons for your furnace to produce a rattling sound. It might be as simple as a loose door cover, so start there. If the rattling continues, the most plausible root cause is a declining blower motor. Treat 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 separated somewhere, allowing conditioned air to escape. These aren’t critical matters, but if you have them fixed quickly, you’ll pay less 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 correspond to 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 offer emergency furnace repair to get your system 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 disappointed with our work anytime in the next 12 months, we’ll fix it! For additional information or to arrange a furnace repair visit, please contact a Service Experts office near you.