You don’t need to know much about science to understand that when water meets metal, there’s a danger of corrosion starting. Corrosion is the term given to the chemical reaction between water and metal in the presence of oxygen. The damage from it causes the destruction of the metal.
There’s one appliance in your home that is particularly in danger of this chemical reaction—your tank water heater. This huge metal appliance stores and circulates water, and yet, it never rusts. How is that possible? Well actually, corrosion is very rare for water heaters, due in large part to your anode rod.
What Is the Anode Rod?
This may sound like a weird term that you don’t need to worry about, and so long as you’re having professional maintenance done on your water heater once a year, you probably don’t need to worry about it. But this rod, also referred to as the cathodic anode rod, runs the length of the center of your water heater tank and is made from two pieces of metal that attract the oxidization ions that cause corrosion.
Essentially, an anode rode corrodes so that your water heater doesn’t!
Therefore, knowing the condition of your anode rod, or having that condition checked, is important. Anode rods don’t last the entire life of your water heater—eventually they corrode completely, and the rest of the water heater is then at risk. This is why, again, maintenance is so vital. That said, you can have your professional plumber show you how to check the anode rod so you can make sure it’s still in good shape between maintenance sessions.
Other Lines of Defense
Your anode rod is your water heater’s main line of the defense, but not the only line of defense. The tank lining helps out a bit here too. The tank itself is made of a durable steel, but the inside lining is made of glass, which doesn’t corrode. It is possible for cracks in the glass to happen though, and then water will be permitted to reach the metal.
Another defensive component is the fact that there’s no air in the tank. A cushion of air used to be included to prevent water pressure spikes, but allowing air into the tank encourages corrosion to begin. So now, there is an expansion tank placed over the main one to absorb any water pressure increases.
“Corrosion Happened, Now What?”
An aging water heater—that is, one that is over 15 years old—may start to corrode no matter how strong its defenses are. It might not be from water but rather from the combustion gases from the burner or some other problem. The best thing you can do if you suspect a water heater problem is to call in a pro!
Not only can we help you with your water heater replacement, but we can fill you in on your various options. A standard electric or gas-powered tank water heater is great, but it’s not all there is out there. You may want to consider a tankless system for efficiency, among other benefits.