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Serving the greater Orlando area

24 hr Emergency Service


Serving the greater Orlando area

24 hr Emergency Service


His team came in and professionally installed the whole system, replacing and sterilizing the ductwork, and cleaning up very well after all of the drywall work and repairs.

- Sean S

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Why Is My Furnace Booming?

It’s a pretty unnerving thing to hear your furnace make a loud booming noise during operation. Don’t worry, though, your furnace is not going to explode. It does very likely have a problem that needs to be addressed, however. There are a couple of different things that can contribute to a furnace making booming noises. Let’s take a look at these issues, and help you determine whether or not you need to call a professional.

Delayed Burner Ignition

A very common cause of furnaces booming is something called “delayed burner ignition.” This is caused by a buildup of carbon on the burner assembly over time. Carbon builds up on a burner assembly because it is a byproduct of the combustion of natural gas. Though virtually all combustion byproducts move through the exhaust flue and out of the house, carbon particles are heavy enough to settle on the burner assembly instead. This buildup can eventually get so high that the burner has issues getting enough oxygen to actually light the gas being supplied through the gas line. When the burner finally does ignite, it tends to ignite all the excess gas at once. This is what can cause a sudden BOOM without any sort of warning.

Duct Flexing

Another common cause of a booming noise coming from your heater is the ducts in your house expanding and contracting. As the warm air moves through your ducts, they react to the heat by expanding. Sheet metal tends to make a good bit of noise when it flexes, which can be a cause of that booming sound. This is especially true in colder climates, where the contrast in temperature results in a greater fluctuation in the ducts.

So which of these two causes applies to you? That will require a professional HVAC technician to actually examine your furnace and ductwork. The duct flexing isn’t really a problem, as long as everything is secured properly. The delayed burner ignition can get progressively worse, however, and may end up in that burner not being able to ignite at all.

If your furnace is making a booming noise, contact Downtown Air & Heat. We provide furnace repairs throughout Orlando.

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