What is the name of the magnesium rod used to prevent corrosion in a water heater?

The magnesium rod utilized in water heaters for preventing corrosion is commonly referred to as a sacrificial anode or sacrificial rod. This component is critical because it protects the tank by corroding itself instead of the metal of the heater, which is particularly important in environments where water chemistry can lead to faster corrosion of the tank itself.

When the tank is filled with water, electrochemical reactions occur that can lead to the deterioration of the tank material. The sacrificial rod, typically made of magnesium, is deliberately installed to be more reactive than the steel of the water heater tank. Over time, as the rod corroded, it provides protection to the tank. This process ensures that the tank remains intact and serves its purpose longer, and thus, extending the overall lifespan of the water heater.

While the term "magnesium anode" could also be applicable, as it directly describes the function and material of the rod, the most broadly recognized and utilized term in the context of water heater maintenance and operation is "sacrificial rod." This highlights the rod's role in actively sacrificing itself to prevent damage to the tank, making it a key component in plumbing systems where water heaters are concerned.