How does my
furnace work?


To understand how your furnace works, you need a general understanding of the basic components. They are:


  • Burners that deliver and burn fuel
  • Heat exchangers
  • Blower
  • Flue that vents harmful gases

You’ll also need to know how your furnace is powered: by natural gas, oil or an alternative source. If your furnace uses gas or oil, here’s a quick explanation of how it works.

Fuel and air are combined and ignited by the burners in your furnace. The resulting flame heats a heat exchanger, a series of metal tubes that stay hot for a long time. Air from your home is warmed when it’s blown across the heat exchanger, and the furnace’s blower distributes this warm air throughout your house through the ductwork.