Why Do Heat Exchangers Crack?
Cracks in metal surfaces are caused by stress and flexing of the metal. Each time your furnace heats up and cools down, this cycle will naturally cause the metal surfaces to contract and expand, applying more stress to the metal and ultimately resulting in a crack or failure of the heat exchanger. This is a natural process that happens to every furnace over time and the rate at which it happens to yours, just depends on how the unit is maintained, and the quality of your installation. If you have ever owned a gas grill, you have seen the cracks that develop around the edges of the metal burner surface. These are very similar to heat exchanger cracks, in the way the metal burner goes through many heating and cooling cycles, eventually developing small hairline cracks. Over longer periods of time, those small cracks eventually turn into bigger cracks. Premature Cracks in the Heat Exchanger As previously mentioned, natural expansion and contraction of the metal surfaces will create cracks
