how long will a furnace last?
The average furnace lasts 15 to 20 years. This life span is typical of a furnace with a stainless or aluminized steel heat exchanger. In contrast, old furnaces with heavy metal heat exchangers last... The average furnace lasts 15 to 20 years. This life span is typical of a furnace with a stainless or aluminized steel heat exchanger.