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What Does a Booming Sound Mean in My Furnace?

shocked-by-loud-noiseIt can be a sudden shock when your furnace turns on during these last cold days of the season and it makes a loud boom sound. You expect to hear a distinct noise when the gas jets on the burner assembly ignite each time, but when the sound becomes something that makes people jump, it can be alarming.

Why does this happen, and does it mean a serious problem with the gas furnace? We have some answers below.

Delayed combustion in the combustion chamber

The booming sound that’s catching your attention is the sound of unburned gas in the combustion chamber suddenly burning up at one time. The combustion gas from the gas jets is not supposed to build up in the chamber, but ignite right away. The booming sound indicates that something is preventing the timely ignition of the gas jets, leading to a sudden ignition of more combustible gas than normal. It isn’t the way the furnace is supposed to run, and can even lead to potential safety hazards.

One reason for the delayed ignition is because of problems with the electronic ignition system. Standing pilot lights are no longer the standard way for modern furnaces to light the gas from the gas jets. Instead, electronic ignition systems such as hot surface igniters or intermittent pilot lights do the job. If the igniter isn’t coming on promptly, it may allow a build-up of combustion gas. Furnaces are designed with safety mechanisms if the igniter doesn’t come on at all that will shut off the gas flow, but you may still experience some build-up. You’ll need to have the igniter replaced, or soon your furnace won’t turn on at all.

The other common cause for the delayed burners is because of an accumulation of carbon particles or grime along the burners. This restricts their ability to access oxygen and ignite. Carbon builds up naturally over the years, and regular maintenance is designed to take care of this. (Yet another reason never to forget annual fall maintenance service.) Dust and grime are also a development that occurs if the furnace is given regular attention. To fix the problem, licensed technicians must remove the burner and clean it with special chemicals to remove carbon and other grime without harming the burners.

Always have professionals check out your furnace

Never attempt a furnace repair in Raleigh, NC on your own. And don’t look to an amateur who makes big promises to do the work either. Natural gas furnaces are potentially hazardous to work on for anyone who lacks professional training. In fact, it’s illegal in most jurisdictions for anyone without a license to work on an appliance connected to a gas main. It may sound as if the problem with a build-up on the furnace burner is easy to repair by cleaning it, but the burners must be detached from the furnace first—and that’s not a task to allow anyone except a professional to do. Let our experts take on the job, and they’ll do it right, and safely, the first time.

Comfort Master Heating & Air Conditioning, Inc. serves the Triangle Area of North Carolina.

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