Most homeowners have heard about heat exchangers but very few know what it actually does. Heat exchangers transfer the heat from the burners into your duct system via the blower. They also transfer the combustion gases out to the flue. For residential furnaces, there are two designs: tubular or clamshell.
Years ago the heat exchangers were cast iron and they were virtually indestructible. With the government mandates for higher efficiency, the cast iron was replaced by stainless steel or aluminized steel. These metals heated up quicker, which improved efficiency.
The life cycle of a heat exchanger is dependent primarily on age and usage. In a typical heating season, a furnace will cycle thousands of times. Each cycle will cause the heat exchanger to expand and then contract when the blower kicks on. The net result, after years of use, is metal fatigue. Eventually, metal fatigue can cause a crack, hole or seam separation which results in carbon monoxide entering your home. At that point, you would have to replace the heat exchanger or the furnace.
Regular preventative maintenance ensures that your equipment is operating at peak efficiency but more importantly it will give you the peace of mind knowing that your family’s safety is not compromised.