Hearing this noise can be alarming, and it should be. You do expect, of course, to hear a distinct sound when the gas jets of the burner assembly ignite as your furnace cycles on. However, when the noise becomes something that makes you jump, that’s cause for concern.
Why does this happen, though? And does it mean you have a serious problem with your gas-powered furnace? Read on to find out!
The booming sound you hear is the sound of unburned gas in the combustion chamber suddenly burning up all at one time. The combustion gas from the jets isn’t supposed to build up in the chamber—rather, it’s supposed to ignite right away. The booming noise signals that something is preventing the timely ignition of the gas jets, leading to a sudden ignition of more combustible gas than usual. This isn’t the way your furnace is supposed to run, and can lead to safety issues.
One reason this delayed ignition happens is due to problems with the electronic ignition system. Standing pilot lights are no longer the standard way for modern furnaces to light the gas from the jets. Rather, electronic ignition systems like hot surface igniters or intermittent pilot lights do the job. If the igniter isn’t coming on right away, it allows for a buildup of combustion gas.
Furnaces are designed with safety mechanisms for cases where the igniter doesn’t come on all—gas flow will be shut off. But this delayed ignition can be dangerous, and it means you need to have the igniter replaced.
Another reason delayed burners happen is due to the buildup of carbon particles, or grime, along the burner assembly. This restricts the burners’ ability to access oxygen and ignite. Carbon builds up naturally over the years, and regular maintenance is designed to take care of this (which is a good reason to never forget annual fall maintenance!) Dust and grime must be adequately cleaned off the burners, and this is something we recommend that only a trained professional do, for furnace functionality and for safety reasons.
Only Trust the Pros for Your Furnace Services
As we alluded to above, furnace repair and maintenance should never be attempted by the homeowner. You also won’t do your system or your home much good by looking to an amateur to do the work—they often have big promises but can’t necessarily follow through when they lack professional training.
Actually, it is illegal in most jurisdictions for anyone without proper licensing to work on an appliance connected to the gas main. It might sound as if the problem with buildup on the furnace burner is easy to repair by cleaning it, but the burners must be removed from the furnace first, and this isn’t a task to give to anyone except an experienced professional. Let our experts handle the job, and we’ll do it right, and safely, the first time.