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Discerning Abnormal Furnace Noises


This blog was prepared by a guest blogger, David Gaudio. David’s blogs are very informative so we wanted to give our readers a chance to benefit from his expertise.

People tend to treat furnace noises like we would in a car. “The noise will go away in a couple of days, no need to call a repairman.” The truth is, that while some furnace noises can be insignificant, others can be deadly. The trick is to be able to discern between the normal and abnormal noises of a furnace. With a little knowledge, certain furnace noises can raise red flags and prompt you to schedule a repair immediately.

Furnace Noises and Meanings

  • Groaning: This usually means that your motor bearings are worn down. I’d recommend scheduling a maintenance check with your local HVAC company to see if your furnace needs to replace your motor.
  • Deep Persistent Train-like Noise: Similar to the groaning noise, this could also indicate that your motor bearings are worn.
  • Squealing: A squeal or whine from your furnace tends to mean an air leak. The air leak could be anywhere and will be hard to pin down without help. These leaks are serious business and you should schedule a repair immediately.
  • Loud Clicking and Clacking: If you have a cracked heat exchanger, your furnace will make this rattling noise about 30 seconds before the blower turns on. Turn off your furnace right now! Cracked heat exchangers are known to lean carbon monoxide, a very deadly nearly undetectable gas. Schedule a repair!
  • Swoosh and Click: The old swoosh and click indicate a leaky gas valve. Immediately turn the furnace and your gas line off to prevent more from leaking out. The next step is to call a professional to find the leak.

Ultimately, every abnormal noise is bad, but some are inconvenient while others are life-threatening. Hopefully, this article has encouraged you not to put off acting on certain furnace noises. A delay could turn a problem into a disaster. Remember all repairs to your furnace should only be performed by a certified professional. A lot can go wrong for the uninformed do-it-yourselfer when dealing with flames and poisonous fumes.

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