What are anodes and how do they work?

Anodes are one of the simplest and most effective ways to help protect a hot water tank from corrosion. They are called “sacrificial” because they break down over time so the steel tank does not.

Corrosion happens when water and metal interact over time. Left unprotected, steel parts inside a tank can begin to rust and deteriorate. An anode is made from a metal that is more likely to corrode than steel, so it draws that corrosive action to itself first. In other words, the anode wears away so the tank has a better chance of staying intact.

In domestic hot water tanks, anodes are especially important in areas where the interior lining cannot fully protect the steel, such as around openings, couplings, inlets, and outlets. These more exposed areas are often where corrosion can begin.

Because anodes are meant to wear down, they do not last forever. They need to be checked and replaced as part of a regular maintenance plan. When they are ignored, the tank can become more vulnerable to damage that may not be visible until the problem is already advanced.