Why Is Moisture a Concern with Furnaces?

Moisture in contact with metal can lead to corrosion, and corrosion in turn weakens metal, eventually causing it to crumble away to nothing. When it comes to metal appliances in your home, corrosion is one of the #1 enemies.

But how does this apply to a furnace? Unlike a boiler, which circulates water as part of its operation, a furnace does not use water to work. It seems strange that a furnace might rust because of moisture, unless there was a flood in the basement where the furnace cabinet is located.

However, furnaces can and do rust because of moisture exposure. When corrosion starts, you’ll need repairs fast or you may end up needing to replace your furnace entirely. We’ll go over why you can encounter moisture concerns with your furnace in Markham, ON.

Call the experienced technicians at Advantage Airtech for all of your heating service needs in Markham.

Moisture and your furnace

Moisture can occur inside your furnace from three different sources. The first is from dampness that can enter through the ductwork from outside. This is most often a problem when the ducts develop leaks that let in external air.

The second source is from trouble with your air conditioner. Usually, an air conditioner sits directly above the furnace unit. If the air conditioner’s condensate pan drain becomes plugged, the water collected from the condensing coil will start to overflow and drip out. If this water gets into the furnace, it will rapidly promote rust. The moment you notice water dripping from the bottom of your furnace, you need to call for both heating and air conditioning repair.

The third source comes from poor exhaust venting inside the furnace. When the combustion gas inside the heat exchangers of a furnace cools down, it turns into a liquid vapor. The reaction between this exhaust vapor and the heat exchangers will eventually cause corrosion; however, the exhaust quickly vents outside through a flue. If this venting becomes inefficient, it will speed the corrosive action between the combustion gas and the metal. A corroded heat exchanger is potentially very dangerous, since cracking along it will permit the escape of carbon monoxide into the cabinet.

Time to replace?

Unfortunately, corrosion on a furnace is often a sign that the system is coming to the end of its service lifetime. If your furnace is over 20 years old and it begins to rust, you should probably schedule a replacement installation before a full break down occurs.

Advantage Airtech has brought quality heating and air conditioning to the Greater Toronto Area since 1987. When you need help with your furnace in Markham, ON, whether because of corrosion or any other repair need, make us your first call.