What is the purpose of a water heater's anode rod?

The anode rod in a water heater serves the critical function of preventing corrosion of the tank. Typically made of magnesium or aluminum, the anode rod is designed to corrode over time rather than the metal tank itself. This sacrificial process protects the tank from rust and degradation, greatly extending the lifespan of the water heater. When the anode rod is in place, it attracts corrosive elements in the water, thereby safeguarding the inner surfaces of the tank from oxidation.

Regular inspection and replacement of the anode rod are important maintenance steps, as a depleted or worn-out rod can lead to accelerated corrosion of the tank, resulting in leaks or total failure. This makes the anode rod instrumental in ensuring the long-term functionality and durability of a water heater, which is why its primary purpose is to prevent tank corrosion.