If your furnace relies on combustible fuels, like propane, natural gas, or heating oil to produce heat, it utilizes a component known as a heat exchanger. In basic terms, a heat exchanger is a barrier formed of thin metal located between the combustion chamber of the furnace and the blower system.
Fumes created during the combustion of heating fuels are called flue gases. The barrier formed by a healthy furnace's intact heat exchanger keeps flue gases from entering into the living areas of the home via the blower, ducts, and vents. Instead, the gases vent harmlessly through the flue to the outside of the home.
Expansion and contraction can cause cracking
One of the most common heating repair issues related to the heat exchanger of a furnace occurs due to the expansion and contraction of the metal from which it is made. Each time the furnace cycles on and produces heat, the metal surfaces of the heat exchanger heat up and expand. When the cycle is over and the furnace stops producing heat, the metal then begins to cool and contract.
Metal fatigue caused by these constant heating and cooling cycles can begin to take a toll on the structure of the heat exchanger, causing it to become more brittle and subject to cracking. As the cracks worsen, increasing amounts of flue gases may enter the blower and then be released into the living spaces of the home.
Carbon monoxide poisoning poses a real danger
While carbon monoxide should not present in the flue gases produced by a furnace in good working order, it is possible if the furnace has a combustion problem that has not been diagnosed and repaired. If carbon monoxide is being produced by a faulty furnace that also has a cracked heat exchanger, it can make its way through the cracks and into the living space of the home along with the flue gases.
Since carbon monoxide is colorless and odorless, occupants can experience serious or even fatal health issues without realizing they are being exposed. Since both combustion issues and cracks or damage to the heat exchanger can occur at any time, homeowners should consider having their system evaluated for these issues on a regular basis.
Heat exchanger replacement should be considered due to age
Homeowners who are using a furnace that is more than a decade in age should consider speaking with a heating repair technician about replacing their existing heat exchanger before a crack or other damage occurs.