How a Furnace Works
If your repair technician just gave you the bad news that your furnace has a cracked heat exchanger, and you said, “ A cracked what?” you’re in the right place. This article is going to go over what a heat exchanger is, why it cracks and what you can do about it if you have a home warranty. To really understand why a damaged heat exchanger is so problematic, and how your home warranty company can help, we have to go over the basics of how a furnace works. How does a Furnace Work? Cracks in your Heat Exchanger and Home Warranties Looking at a furnace quite simply, it has four main parts that allow it to heat your house: Draft Motor The first is the draft motor. The draft motor kicks on when there’s a drop in temperature in your house, and your thermostat tells your furnace that warm air is needed. When this happens, your draft motor begins to pull ambient air into the unit from the surrounding area. Burners As air is taken into the furnace to be warmed, gas is turned on in the burners of the furnace. The furnace ignites this gas with a spark, and the burners create a flame. This flame produces hot gasses that go into the heat exchangers. Heat Exchangers Heat exchangers are a series of metal tubes that heat up and stay extremely hot. They hold the hot gasses and carbon monoxide the burners produce. These gasses are poisonous, so the heat exchangers are attached to a flue that vents the gasses outside. Blower As the draft motor brings air into the furnace, the blower motor begins to force air past the extremely hot metal tubes of the heat exchangers. Obviously, the hot gasses from the burners that are inside of the heat exchangers don’t mix with this air, unless they have a crack. As long as the heat exchangers have an air-tight seal, the air is simply blown over them. This warms the air up, and the blower continues to push the air throughout your ductwork, providing warm air through your house. If your heat exchanger is cracked, however, this could prove problematic for homeowners. There is a possibility that those poisonous gasses from your burners could leak into the air being blown throughout your home.
