Negative Effects of Corrosion Rods in Water Heaters

Corrosion Rod

• The corrosion rod in your hot water heater exists to prevent the tank from rusting through and destroying itself. The corrosion rod is often called a sacrificial rod because it acts as a sacrifice. It corrodes so the rest of the tank does not. Corrosion rods are typically made of magnesium, which corrodes faster than other metals. During the corrosion process, it sheds electrons. These electrons go to the water tank’s lining, creating a rust-resistant environment around the lining.

Negative Effects

• While corrosion rods prevent your hot water tank from rusting out in a year or two, they can cause negative effects in your hot water supply. The ions they release attract a kind of bacteria known as sulfur-reducing bacteria. These bacteria produce hydrogen sulfide gas as a waste product. When they infest your hot water tank, the hot water in your home will reek of rotten eggs. You won’t be able to use hot water for bathing or washing until you get rid of the bacteria.

Solutions

• Kill the bacteria in your hot water heater by raising the temperature of the water in the tank to 160 degrees Fahrenheit and leaving it at that temperature for a few hours. The heat kills the bacteria. Lower the temperature and flush the water filled with bacteria out of the tank, then let it refill. This is a temporary solution, because the bacteria could return, attracted to the corrosion rod. Removing the rod will prevent the bacteria infestation, but will void your hot water heater’s warranty and leave it vulnerable to rust.

Considerations

• You can try replacing the magnesium corrosion rod with one made of zinc. The zinc rod will also release electrons and protect the tank, but it is not as attractive to sulfur-reducing bacteria. Contact a plumbing professional before you make any changes to the corrosion rod. If you prefer to leave the rod alone, continue to raise the tank temperature and flush the water at the first hint of the smell of rotten eggs in your water. Acting early will help prevent the smell from getting too strong.