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W.C. Butler Heating and Air Conditioning Blog

Don’t Ignore These Heater Noises


During this time of year, there are probably some noises you welcome. Maybe carolers traveling through your neighborhood, or holiday music on your radio. There are other noises, however, that aren’t so pleasant, and definitely should never be turned out or ignored–we’re talking about strange noises coming from your heater.

Now, there is not such thing as a completely silent heating system. You will always hear it cycle on and off. Plus, if you’re using a furnace that has ductwork, you might hear a slight rattle as the ducts expand and contract with temperature fluctuations. And then of course, you’ll hear the whoosh of air coming through the vents.

You really shouldn’t hear much beyond this, though. If you notice noises that you’ve never heard before coming from your heater, no matter how subtle, it’s probably time to give us a call. Read on as we uncover what some of these noises might be.

A “Boom” or “Bang” At System Startup

Let’s start with the noise that often alarms homeowners the most–a loud banging or booming noise coming from a gas furnace. If you hear this sound happen consistently, there may be a problem with the system’s ductwork or the sheet metal siding of the furnace expanding and contracting–due to either poor installation or improper heating system sizing.

However, if this sound is only occurring during system startup, then you have a good reason to be concerned. The noise can be something as relatively benign as a dirty furnace burner. The problem is, though, that the layer of dirt or grime enables gas to buildup, causing a short of mini-explosion when the burners do ignite. This might not affect the system right away, but what it does is rattle the heat exchanger, which can eventually cause damage and leave you susceptible to carbon monoxide exposure.

A Squealing Sound

Any squealing sound that you hear from your furnace may be the result of a lack of lubrication or even a blower fan belt that is wearing down. These are both easy fixes for our technicians, however this doesn’t mean it’s a repair need to be put off.

If you let this problem go on for too long, the fan will stop working altogether, disallowing your furnace from functioning when you need it the most. It’s far better to have your furnace repaired at the first indication of a problem rather than wait for it to turn into a bigger and more expensive repair, or potentially even a premature replacement.

A Low Rumbling

This can definitely seem like a pretty concerning sound. We can’t say with absolute certainty what the noise is without taking a closer look ourselves, but one common explanation is that the pilot flame is too low.

Check the flame of your furnace to confirm that it is blue rather than yellow or orange. Otherwise, that rumbling sound may be attributed to a harmful carbon monoxide leak.

For expert service on your furnace in Botetourt County, VA, look no further than W.C. Butler Heating and Air Conditioning. Contact us today!

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