How does an anode rod protect the water tank from corrosion?
Cathodic protection is accomplished in the glasslined or galvanized water heater through the use of an auxiliary magnesium anode. Due to the relative position of magnesium to steel in the electromotive series of metals, magnesium will corrode producing an abundance of electrons which flow (much the same an electrical current) to the exposed steel surface and maintaining it in the electro- negative state. As current flow takes place, the anode rod reacts chemically to corrode at a rate faster than the steel inner tank. This process stops tank corrosion by substituting the sacrificial magnesium anode rod in place of the steel tank. As long as the magnesium anode rod remains in the tank, in an active state, there will be no corrosion of the minute areas of exposed steel inside the tank.
