magnesium rod for water heater

详情

Cathodic Protection is accomplished in the glass linved water heater by using 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 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 sacrificail 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 explosed steel inside the tank.

The life of the anode, in turn, depends on water temperature, amount of water used, and the quality of the glass lining. However, the most important factor in the life of the anode rod is the water chemistry, the hardness or softness of the water.

Water softeners contribute to the change in water chemistry. In directly, softened water acts to reduce the service life of the anode,since its current demand becomes drastically higher. Also, check the manufacture and installation date of the water heater.

If the heater is more than five years old, and the anode rod has not been replaced, inspect the anode rod. The anode should be replaced when there is six inches or more exposed core wire at either end.