Most people heat their homes using either a boiler or a furnace. But what's the difference between these two common heating systems?

A boiler heats water and then transforms it into steam or hot water. The steam or hot water is then circulated through pipes to radiators or baseboards which provide warmth to the rooms in your home.

Furnaces, on the other hand, heat air and then circulate it through the ducts in your home. The warmed air is then distributed through vents, which provide warmth to the rooms in your home. Furnaces are typically used in homes with forced-air heating systems, where the heated air is circulated through ducts.

Boilers are often called furnaces by homeowners. This statement is actually correct, while a furnace is not a boiler, a boiler is technically furnace. Plumbing and heating professionals typically refer to boilers when discussing forced hot water systems and furnaces when discussing forced hot air.

So, what's the main difference between boilers and furnaces? Boilers heat water while furnaces heat air.