Older furnaces are, unsurprisingly, less efficient. The average lifespan of a furnace is about 20 years. Depending on how much fuel your furnace wastes, you can calculate how much money you’re unnecessarily spending every month. The AFUE number describes the percentage of fuel consumed and how much is wasted. If you don’t know your furnace’s AFUE rating, you can call the manufacturer with your serial number to find out. The significantly lower energy bills that come with a newer, more efficient furnace can help you recoup the expense of replacing your system.
The EPA recommends that you replace your air conditioner if it’s over 10 years old. A newer system will operate more efficiently and, in turn, can save you money on your energy bill.
It might be time for a replacement if your old system: