If I buy a new furnace how much money will I save on my gas bill?
This question cannot be answered definitively as there are many points to be considered. If you are replacing a 30 year old standard 55 to 65% efficient furnace, you will save more on your fuel costs than you would if you were replacing a 10 year old mid efficient 80% furnace. You also have to keep in mind some other factors such as the price of natural gas, as well as the outdoor temperatures. If we have a mild winter you will use less gas, and will save more money. If we have a colder winter, the furnace will run more often which will cause your furnace to burn more gas.