What is the Heat Exchanger?
The heat exchanger (the heart of your furnace) is hollow tube metal which allows ignited natural gas to pass through the inside of the tubes. The spent gas is then discharged into a 4 inch round duct called the flue and the gas is emitted out the roof of your home. You can see the spent gas on really cold winter days, (what looks like steam coming out of vents on roof tops). The heat is transferred to your house by the blower motor which draws air back to the furnace via the return air vents in your home. The return air is then forced through the heat exchanger. The air warms by removing the heat off the heat exchanger surface (the outside of the tubes) discharging the heated air into your home.

How does the heat exchanger get cracked?

Your furnace turns on & off hundreds of times a year. The heat exchanger is made out of metal which expands when heated and contracts when cooled. Over the years this will produce hairline cracks in the heat exchanger. (This is a common result in most furnaces)

How does a leaking Heat Exchanger endanger my health?

When your furnace turns on for heat, the burners ignite the main gas which heats up the heat exchanger to a set temperature. The small induction fan located just above or below the burner removes the spent gas via the flue. The main blower motor that draws back the return air from your house comes on after the heat exchanger gets hot The gas burners will continue to come on and off to maintain the temperature of the heat exchanger through out the heat cycle. If you have a even a hairline crack in the heat exchanger when it heats up it will expand and allow carbon monoxide to escape into the main duct that is used to deliver air to heat your home. As soon as the blower motor turns on the gas will discharge into your living space. Although the amount of gas in the air is minuet (150 parts per million per hour is considered a hazard per the AGA (American Gas Association)), this happens every time your furnace turns on and every time the burners turn on to maintain the temperature of the heat exchanger. On cold days your furnace can cycle on between twenty, thirty or more times. This can become a hazard.