The average Maine homeowner spends between $2000 and $5000 per year on fuel to heat a family home.   Added to this annual expense is the amortized cost of purchasing and maintaining a heating system which can be as high 25% of the annual fuel price.  Efficiency Maine has an excellent fuel cost comparison tool to allow consumers to compare current fuel costs for a typical Maine home, but not all heating system decisions come down to cost.   The optimal heating system choice will depend on age and design of the home, existing heating system, fuel availability, service and maintenance costs, and home owner desire to reduce carbon production.