The energy savings below are estimates only that serve as guidance in a homeowner’s furnace purchase


  1. Select the efficiency of your current furnace. (See help below.)
  2. Enter your exact or estimated yearly gas costs*

*Rather than guessing, we recommend taking your current yearly heating bills to determine your estimated future operating cost savings

Current Furnace Efficiency

Current Yearly Operating Cost

New Furnace Efficiency


10-Year Savings
20-Year Savings

Need help determining your current efficiency? Check the flue pipe coming off your furnace. (This is a 2-5″ diameter pipe exiting your furnace that vents waste gas.)

If the flue pipe is metal your furnace is 80% or below. If the flue pipe is white PVC plastic your furnace is 90% or greater.

The chart below helps determine your likely efficiency if you have a metal flue.

Furnaces with metal flue pipes
Furnace Age
0-19 years
20-29 years
30+ years
Average Efficiency

What does the ‘%’ mean? A furnaces efficiency has an AFUE rating which is measured in a percentage.

The higher the percentage, the more efficient the furnace is. A more efficient furnace costs less to operate as shown in the table above.

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