Is your furnace a fire hazard?

Over the years, there have been many furnaces manufactured that have had recalls due to documented evidence that they present a fire hazard, carbon monoxide hazard, or both.  These are obviously something that a potential home buyer needs to know during their inspection period.  One of the most well known furnaces that has had these issues is one manufactured by Consolidated Industries.

Consolidated Industries is actually no longer in business.  They went bankrupt after issue after issue crippled their business.  The most notable time period that they were manufacturing defective furnaces was between 1983 and 1994.  Now, you may be reading this thinking to yourself, "that was a long time ago, and there probably aren't hardly any of those furnaces around anymore."  Think again. There are thousands of those furnaces still in use today by many homeowners, and the scary thing is that they probably have no idea of what kind of monster is sitting in their attic.

Consolidated Industries has manufactured furnaces under numerous name brands throughout the years, such as: Amana, Coleman, Kenmore, Premier, Sears, and Trane just to name a few.  The furnaces they were making that were problematic were the horizontal furnaces mounted in the attic, that had the burners on the bottom.  The problem with these furnaces that was creating a fire hazard, was that they were mounted on plywood attic decking, and although they were rated for installation on combustible surfaces, heat was passing from the burner compartment through the bottom panel of the furnace and igniting the wood decking or ceiling joists below it.  This was not the only problem, however.

The methods of manufacturing and design of the furnace was the underlying issue.  The design of the burner tubes, gas manifold, combustion gas valve, and pilot assembly were all problematic.  Small cracks were developing in the metal webs between the gas port openings and individual burner tubes.  Once the cracks are there, continuous use of the furnace only causes them to grow.  Continued expansion and contraction of the metal added to the stress on the furnace components that lead to failure.  The larger the cracks became, the more likely it was that flames from the burners could escape and grow very large, some of which were documented to be up to 9 inches in length, which eventually would cause the heat exchanger to crack.  Once the heat exchanger is cracked, is when all hell can break loose.

Combustion gases, such as carbon monoxide (which is odorless, by the way), are now being drawn through the cracks in the heat exchanger, where it mixes with the air that is circulating through the ductwork of the home, and is being dispersed into the living space.  This is a very, very bad situation.