What Is Anode In Water Heater?

Have you ever wondered what is the purpose of a long metal rod inside your water heater? This rod serves an important role for efficient functioning and safety of your water heater.

It is called an Anode. There’s a certain type of magic to this metal rod, which helps to protect your water heater from corrosion and extend its life. In this article, we will explain what an Anode is, how it works, and why it’s important to maintain it.

So keep reading to learn more about the mystery behind this metal rod.

What is an Anode in a Water Heater?

An anode in a water heater is a metallic rod that is used to protect the metallic surface from corrosion by acting as a sacrificial anode. This rod is normally made of either magnesium or aluminum and is inserted into the tank of the water heater.

Corrosion occurs when an electrically charged metal, such as an anode, is immersed in water containing dissolved oxygen that is acidic or alkaline in nature. The anode will create a negatively charged environment, which can help prevent corrosion on the tank walls by acting as a sacrificial anode.

Types of Anode Rods

There are two types of anode rods that are commonly used in water heaters:
  • Aluminum anode rods: Aluminum anode rods are less expensive and are the most common type found in newer water heaters. However, this type of anode rod does have a tendency to corrode more quickly than its magnesium counterpart.
  • Magnesium anode rods: Magnesium anode rods provide better corrosion protection and last longer than their aluminum counterparts but are more expensive.

Advantages of Anode Rods

Anode rods are an important part of water heater maintenance as they provide many key benefits, including:
  • Helps extend the life of the water heater.
  • Helps to prevent corrosion and rust.

  • Protects the water heater from hard water.
  • Helps reduce maintenance and repair costs related to water heater corrosion.

Replacing Anode Rods

Anode rods should be replaced every two to five years depending on their condition.

Depending on the water heater model, the anode rod may be able to be unscrewed or it may need to be cut off. When replacing the anode rod, it is important to use the same type of metal as the original rod.


Anode rods are an important part of water heater maintenance and can help protect the tank from corrosion and extend its life. Be sure to replace the anode rod every two to five years or according to the manufacturer’s instructions for optimal protection. By following this maintenance routine, you can help keep your water heater running longer and prevent costly repairs.

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