What Is the Sacrificial Anode Rod?
February 16, 2015
A water heater has a few vital components that make it possible for water to heat up and flow into the faucets and sinks in your home. The dip tube is a long pipe through which cold water enters at the top of the tank and flows all the way to the bottom. The burner at the bottom of the tank heats up the water, using natural gas and an ignition source for heating. Or, if you have an electric water heater, the electronic heating elements at the bottom and upper-middle portions of the tank heat up the water, which then naturally rises to the top of the tank. Finally, a small tube at the top allows the water to flow into the faucet.
The sacrificial anode rod is one of the most important components of the storage tank water heater, yet it doesn't participate in this heating process at all. But it does serve an equally important role: keeping the tank from rusting. The water heater is made of steel-an iron alloy-and anything made of iron that comes into contact with water risks corrosion. Only three things must be present in order for something to rust: iron, water, and oxygen. And rusting always leads to corrosion. As holes start to form in the tank, water may leak into your home. Most experts recommend replacing the tank at the first sign of rust to prevent this from happening.
Most water heater tanks have a lining that keeps the tank from rusting for a time, but it's not thick enough to ward off rust for its entire lifespan. Thankfully, the sacrificial anode rod attracts the particles that cause corrosion. This is a small rod that sits in the middle of your water heater tank and essentially sacrifices itself for the good of the tank. During this heroic deed, an anode rod may wear down entirely, until it gets to the point where it can no longer serve your tank. Occasional maintenance is necessary so that a technician can examine your tank and replace your anode rod if it is too worn down.