The furnace is the true workhorse of heating across North America: gas furnaces and electric furnaces are the heating systems most commonly found in residential buildings, and that isn’t likely to change soon, even with the growing popularity of heat pumps.
Because furnaces are so common, it’s easy for people to think that the furnace in their home will just keep running forever. Of course, no furnace is immortal, and it’s important to know when you need to replace yours.