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 noises. Some noises — like a couple of faint pops or clicks ahead of the warm air beginning to blow — are normal and harmless. But others could impair the equipment or even endanger your health if you dismiss them. While there are many more furnace noises to consider, here are nine that justify an immediate furnace repair.
Scraping Furnace Noise
The moment you hear a sound like metal rubbing on metal, this could mean the blower wheel is becoming detached from the motor shaft, or the wheel or motor mount has broken. Regardless of the specific problem, you should switch off your furnace if you notice a scraping sound and call a professional for an emergency repair.
Loud Boom at Startup
When your furnace starts up, the burners should ignite quickly and begin heating your home. A loud boom at startup probably means the burners are dirty, producing a delayed ignition. When the gas at last does ignite, you hear this scary furnace noise.
A small blast each time your furnace turns on could crack the heat exchanger, a pricey repair that might require you to switch out the entire furnace. Act before it gets to this point! Shut 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 screaky or loud squealing furnace noise generally indicates poor lubrication. Shaft bearings and other moving parts require lightweight oil to run smoothly. Without this, components grate 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 caught in your furnace absolutely warrants investigation. If you perceive 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 cases like this, the sound should dissipate after a few cycles.
However, if the chirping doesn’t subside, it could imply the pulley for the blower motor is crooked or the mounting plate is contacting the blower wheel. This isn’t necessarily a safety threat, but the only choice to eliminate the annoying furnace noise is to have a technician conduct a repair.
Screeching Furnace
Screeching noises are an unmistakable warning sign that the fan belt is wearing out. If the fraying belt cracks, it could create all kinds of issues inside the furnace, harming 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 flip on and off. This is completely normal. That said, if the noise lasts longer than a minute or so, this could indicate an electrical problem. To avoid risking a house fire, call a furnace repair professional to correct the problem promptly.
Thwapping Sounds
The blower motor should operate 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 hitting it with each rotation. A quick repair should be all it takes to eliminate this pestering furnace noise and prevent 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 start there. 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
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 loose, allowing conditioned air to release. These aren’t critical matters, but if you address it promptly, you’ll spend less on your heating and cooling bills long term.
Schedule Furnace Repair with Service Experts Heating & Air Conditioning
Are you unsure whether the furnace noises you hear match these descriptions? It might be nothing, 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 back up and running as fast 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 fix it! For more information or to arrange a furnace repair visit, please contact a Service Experts office near you.