When you’ve been using your gas-powered furnace flawlessly all winter long, and then suddenly you start hearing unusual noises coming from it, you may be alarmed. Sure, you expect to hear some noise when your furnace starts running—you’ll hear it cycle on and of course you’ll hear the whoosh of warm air coming through your vents.
What you shouldn’t be hearing though, is a boom shortly after the furnace turns on. What does this mean? More on that below.