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Is Your Heater Haunted? Strange Furnace Noises Explained

The film industry uses professionals to called foley artists to create sounds effects. They’re masters of using ordinary items to produce specific sounds. For example, the head of lettuce hurled against a wall has the sound of a devastating punch.

We mention all of this because a foley artist would have a field day recording the sounds an old furnace makes. Squealing, banging, thumping, scraping would make eerie noises for, say, a movie about a haunted house. If you hear anything strange from your attic or basement, your home (probably) isn’t possessed. A more likely explanation is that your heating system is malfunctioning. Here are four common HVAC sounds that could keep you up at night.

Squealing

If your furnace is wailing like a banshee, it’s likely an issue with the motor bearing or fan belt. A ¼ horsepower motor operating at 1200 RPMs can make a racket if it’s not lubricated or the bearings are out of alignment. You should schedule an appointment with an HVAC technician right away because you’ll be without heat if the motor breaks down.

Banging/Popping

Those popping sounds aren’t gremlins crawling through your air ducts. Ducts expand or contract with changes in pressure. It’s generally nothing to worry about. But if you can’t live with the noise, you have a couple of options:

  • Insulate your ducts: Insulation will dampen the noise, but that’s just a side benefit. Duct insulation will minimize heat loss, helping your HVAC operate more efficiently.
  • Replace your ducts: Square ducts are most prone to pop. Circular flex ducts handle more pressure and are therefore quieter.

Scraping

Does your furnace sound like a deranged lunatic slowly dragging his ax across the floor? Blame the blower wheel. The blower wheel is responsible for moving large volumes of air through your ducts. The wheel can come loose and scrape against the casing.

Bottom line: Properly functioning, an HVAC system should operate pretty much soundlessly. Any unusual noise should be investigated by a heating and air conditioning technician. To schedule your appointment, call AAA Service Plumbing, Heating & Electric at. (303) 622-3449.