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Understanding The Threat Of A Cracked Heat Exchanger

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Like all home appliances, furnaces are likely to develop certain problems as time goes on. Yet unlike appliances such as washing machines and refrigerators, a malfunctioning furnace represents a potentially deadly problem, especially if it involves carbon monoxide gas leaking out into your home. A cracked heat exchanger is one furnace problem that can allow just this scenario to occur. If you would like to hear more about this problem and why it is so serious, read on. This article will discuss what causes a heat exchanger to go bad, as well as what a professional HVAC repair person can do to identify and fix the problem.

The Heat Exchanger

To begin, it helps to understand a little bit more about the role of the heat exchanger inside of your furnace. As its name would imply, this is the place where heat is transferred from the heart of your furnace to the air that will circulate into your home. Naturally the two systems must remain separated, since the air inside of the furnace contains exhaust gases and other dangerous by products. Thus the furnace's internal air passes through the coiled metal tubes of the heat exchanger, which transfers the heat to the air of your home. Meanwhile, the exhaust fumes pass harmlessly out of your home through the furnace vent.


As noted above, the heated air being generated by your furnace contains a diverse array of combustion by-products. A number of these substances are highly corrosive. Over time, they will cause your heat exchanger to develop patches of rust. Eventually small holes may form in the walls of the exchanger.

Not only that, but the heat exchanger is subjected to constant--and large--fluctuations in temperature. Ultimately, after years and years of such abuse, this will lead to what are known as expansion stresses. In other words, the constant expansion and contraction of the metal will cause it to warp and bend, opening up cracks along seams and in other structurally weakened areas.

Diagnosis And Repair

A furnace technician can diagnose a cracked heat exchanger using a variety of different methods. The most basic is to perform a visual inspection of the exchanger, noting any visible patches of corrosion or any holes. They may also utilize an infrared camera, since any cracks will not just be allowing fumes to escape but also heat. Finally, they may use a carbon monoxide detector to further confirm their findings.

Small cracks or holes can be repaired by a patching on a fresh piece of metal. More systemic problems, however, will require that the entire heat exchanger be replaced in order to adequately protect you and your family. Visit websites like http://www.cdcoolingheating.com to learn more.