What sort of home appliance do you think is most likely to corrode? You’ll probably think of the water heater, or shower heads and other water-using fixtures. You probably don’t think about your gas furnace rusting. It doesn’t use water to warm your house, after all. It applies heat to the air through a metal heat exchanger that contains hot combustion gas.
But furnaces can rust, and many do. It can be a minor irritation, a sign the furnace is too old and needs to be replaced, or even a major safety hazard. Let’s look a bit more into how corrosion can affect a furnace and what it means.