How long can you expect your furnace to last? And what should you be looking for when it's time to get a new one?
As a furnace gets old, the cost to maintain it and replace worn out parts goes up. Technology has improved, making new units more efficient and cheaper to operate than old ones. So once a furnace is 15- to 20-years-old, or if rust or corrosion are visible inside, it may be time to say out with the old and in with the new.
In colder climates, look for the system with the highest efficiency you can buy. In milder regions, 80 percent is probably high enough. It's a good idea to look for a "sealed combustion" system that burns air from the outside. That way you don't burn air you've already heated. Finally, have a professional figure out the right size furnace for your home. It's a difficult calculation and one that requires some experience.
Depending on the size and efficiency you want, expect to pay somewhere between $1,500 to $3,500 to bring home a new furnace.
