Rust is a major threat to homes, and has been since humans first started using iron. The effect of rust on metal is a reduction in strength that eventually leads to metal flaking away to nothing. If you notice rust on major appliances, it usually means you need to call for repairs… and you may need to replace the appliance entirely.
How does this apply to a furnace? Furnaces, whether gas or electric, do not use water and shouldn’t come in contact with it—unless through flooding—so it seems logical that rust would rarely threaten them. However, furnaces can rust… and often do. When this happens, you need to call for furnace repair from Littleton, MA professionals. Basnett Plumbing & Heating does extensive work with all types of furnaces, and we can help you when corrosion strikes your furnace.
How Rust can Affect a Gas Furnace
Many homeowners are unaware of this, but moisture actually is part of a gas furnace’s heating cycle. When the combustion gas from the burner gathers inside the heat exchanger, it changes into a liquid vapor as it cools down. The vapor then vents out the exhaust flue. However, prolonged exposure between combustion vapor and the metal of the exchangers will lead to corrosion—especially if the furnace isn’t venting correctly.
Corrosion on a heat exchanger is a potentially dangerous situation, since it can lead to carbon monoxide leaks. This is the main reason rust on a furnace must be remedied as soon as possible. Annual maintenance will check to see if rust is developing along the exchanger, and replace the exchanger when necessary and look for the problem with venting.
Rust will often start to occur on a very old gas furnace simply because of the long years of reaction between the combustion gas and the metal. Usually, this is a sign that the old furnace needs replacement.
What about Electric Furnaces?
Rust can also affect an electric furnace. Moisture from humidity often enters the ventilation system attached to the furnace, coming through the intakes and into the cabinet. There is also the potential problem from a malfunctioning air conditioner evaporator coil, which is usually fixed above the furnace. If the AC develops an overflow in its condensate pan, water will drip down onto the furnace and cause it to rust. If you see moisture dripping from your furnace, call for repairs. (Both of these issues can affect gas furnaces as well, by the way.)
Repair—and Prevent—Furnace Rust
You may need to replace a heavily rusted older furnace. But if you catch the rusting soon enough on a younger furnace, professional repairs should be able to fix it. The best way to catch the trouble before it turns into a replacement is to schedule regular maintenance. Contact Basnett Plumbing & Heating to sign up for our Ultimate Maintenance Agreement and help avoid future repair in Littleton, MA for a rusty furnace.