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Wow, My Furnace Is Noisy! Is That a Problem?

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“A sound so high-pitched, only dogs can hear it.” You’ve probably heard this phrase before, and it’s true that we dogs have a much better sense of hearing than humans. We can hear four times as far as you and hear high-pitched sounds between a range of 67,000 to 45,000 Hz. By comparison, you humans can hear in the range of 64,000 to 23,000 Hz. We also have a bunch of extra ear muscles so we can track sound direction.

But despite all our great hearing, we can’t actually tell you about noise problems in your furnace. It’s something you’ll have to figure out yourself. When your furnace begins to make odd noises that are a racket to your less sensitive human ears, you’ll probably wonder if you’ve got trouble that needs professional furnace repair in Knoxville, TN.

So What Do Those Furnace Noises Mean?

They could mean anything from a tiny issue like a loose furnace cabinet door to a warning the entire furnace is just too old and it needs to be replaced. Specific sounds can indicate specific problems, while general noise pollution from a furnace is a sign of old age catching up to it. Let’s take a closer look:

  • Rattling: This might be as simple a trouble as an unlatched furnace door. Check to make sure it’s secure and see if the noise keeps up. If it does, the cause is probably a loose mechanical part, and it’s best to allow a professional to check on it and see what’s wrong.
  • Shrieking: A mechanical shrieking noise is associated with a motor with bearings that are wearing down. If the bearings completely wear down, the motor will suffer from harsher wear and is more likely to fail. If you catch the problem in time, professionals can simply replace the bearings and the motor itself won’t need a replacement.
  • Screeching: This is often the sound of a motor that’s about to burn out because of stress (it may be lack of lubrication, extra dust on it, etc.) In most situations, the motor will have to be replaced.
  • Booming: You turn on a gas furnace, there’s a pause before the burners come on, and when they do you hear a startling boom from the cabinet. (Yes, this will startle your dog!) What’s happening is delayed ignition is allowing unburned gas to build up in the combustion chamber, so when the igniter finally works, a large amount of gas burns up at one time. You’ll want whatever is causing the delay to be fixed right away.
  • Clicking: This can mean the transistors to the blower motor are failing, which will soon mean a motor that doesn’t work. But if you hear this sound after the blower motor turns off, you might have a cracked heat exchanger—a serious issue that could create health hazards! Shut off the furnace and call for technicians right away.

Again, if your furnace is simply noisy all the time, making a rattle-and-clang you don’t expect from it, it’s likely the furnace is too old (more than 15 years) and it’s time to have it replaced. You can trust our professionals to help you make the best choice for your heating system’s future.