Replacing an anode rod in a hot water heater tank

Anode Rod

Originally contributed by • last updated 2/24/2021


As a homeowner, there are many things around the house that require you to perform regularly scheduled maintenance. Some tasks may be as simple as changing a light bulb when it burns out while other tasks could be as complicated as replacing your water heater. Luckily, for the majority of homeowners, hot water heaters require very little maintenance to keep them working properly. However, the sacrificial anode, which is also known as the anode rod, is one part that will probably need to be replaced every few years.


The term anode rod, sometimes deemed the sacrificial anode, typically refers to a replaceable metal rod, most commonly made from either aluminum, magnesium, or zinc, that screws inside a hole in the top of most hot water tanks. Through an electrochemical process, anode rods are designed to attract the corrosive elements in the water, protecting the steel metal walls inside the hot water tank from oxidation and deterioration. In other words, the aluminum or magnesium is sacrificed to the corrosive elements, saving the metal walls of the water tank from eroding. Powered anode rods are a type of non-sacrificing anode rod that produces an electric pulse to prevent corrosive elements from causing deterioration.

What Are Some Signs That Your Anode Rod Is Bad?

If you have a traditional water heater, you’re probably going to need to replace the sacrificial anode rod at some point in time. That’s because, unlike powered versions that prevent corrosion through an electrical process, traditional sacrificial anodes are designed to self-destruct. As a result, you’ll need to stay on top of your regular maintenance and watch out for these signs of deterioration:

  • Be on the lookout for rusty colored water and/or water that smells bad like rotten eggs. Discolored water and a sulfur smell could be a sign of oxidation and deterioration in your tank as the result of a bad anode rod.
  • In general, your anode rod should be replaced every three to five years. It’s a good idea to check your hot water heater’s manual or contact the manufacturer for a regular maintenance schedule.