And not all furnaces use natural gas, although most do. Your furnace may run on propane, heating oil, or electricity.
Welcome to Furnace 101, where we teach you the basics of your furnace and how it works to provide heating to your home.
The most common type of furnace is a gas-powered central air system, which heats air in a one area and then distributes it throughout the home via ductwork and vents.
Your furnace starts when it receives a signal from the thermostat that tells it to turn on. Depending on the temperature you set, when the thermostat detects the air temperature dropping below that number, it activates the furnace.