How to Cheaply Replace Your Furnace

Consult with a contractor to determine what the optimal size furnace is for your house and living conditions. This costs money up front, but will save you money in the long run. A house that has an over-sized furnace uses more energy, and the initial cost of the furnace is more. Contractors consider the size of your house, how many exterior walls there are, such as those for a town home versus a freestanding home, how many people live in your house, the types of windows and local climate.

Replace your furnace after 15 years. Most furnaces only work efficiently for 15 years -- and it's usually during winter when this happens, leaving you desperate to replace it. Instead, start looking for the best deal when your furnace is about 15 years old, so you can save money in the long run.

Shop in the spring or summer for furnaces. Off-season shopping means that furnaces are on sale. You can get a much better deal at this time, rather than buying in the fall or winter, when everyone is anticipating the cold weather.

Offer cash for the furnace. Some retailers will offer a discount for people paying cash -- and you will save money by not paying interest on a credit card. If you do use a credit card, consider using one that pays back a percentage of what you spend on it, such as a dividend credit card, and pay it off as soon as possible.