We are independent & ad-supported. We may earn a commission for purchases made through our links.
Advertiser Disclosure
Our website is an independent, advertising-supported platform. We provide our content free of charge to our readers, and to keep it that way, we rely on revenue generated through advertisements and affiliate partnerships. This means that when you click on certain links on our site and make a purchase, we may earn a commission. Learn more.
How We Make Money
We sustain our operations through affiliate commissions and advertising. If you click on an affiliate link and make a purchase, we may receive a commission from the merchant at no additional cost to you. We also display advertisements on our website, which help generate revenue to support our work and keep our content free for readers. Our editorial team operates independently of our advertising and affiliate partnerships to ensure that our content remains unbiased and focused on providing you with the best information and recommendations based on thorough research and honest evaluations. To remain transparent, we’ve provided a list of our current affiliate partners here.
Materials

Our Promise to you

Founded in 2002, our company has been a trusted resource for readers seeking informative and engaging content. Our dedication to quality remains unwavering—and will never change. We follow a strict editorial policy, ensuring that our content is authored by highly qualified professionals and edited by subject matter experts. This guarantees that everything we publish is objective, accurate, and trustworthy.

Over the years, we've refined our approach to cover a wide range of topics, providing readers with reliable and practical advice to enhance their knowledge and skills. That's why millions of readers turn to us each year. Join us in celebrating the joy of learning, guided by standards you can trust.

What is an Anode Rod?

By Terrie Brockmann
Updated: May 17, 2024

An anode rod is a component of a water heater that helps to prevent internal corrosion. The rod, often called a sacrificial anode rod, attracts the corrosive elements in water and allows them to dissolve it. This slows the corrosion of the tank's liner. Almost all water heaters have the rods, though some smaller tanks, such as recreational vehicle water heaters, may not. Homeowners can replace the anode rods when they begin to deteriorate.

When different types of metal are exposed to each other, usually there is an electrical flow of current between the metals. As hot water heaters have various metals, such as copper piping, steel tank walls, and brass fittings, they have erosion from the electrochemical reaction. Anode rods are made of aluminum, magnesium, or a combination of metals. The sacrificial metal is wrapped around a steel wire or thin rod. In a cathodic protection action, the sacrificial metal allows the electrochemical reaction to attack it instead of essential parts of the water heater.

Aluminum anode rods are very effective in areas that have hard water. Some people have concerns about the negative health effects of aluminum; therefore, experts advise that people not use water from a hot water tank for drinking or cooking. The owner's manual usually lists what type of rod the manufacturer used. Sometimes homeowners smell a sulfuric, or rotten eggs, smell from the hot water. Often installing an anode rod made of aluminum and zinc will dispel the smell.

Magnesium rods are the most common type. Where there is hard water, they are not as effective as aluminum rods. Generally, there are no known health problems with the magnesium rods.

Experts suggest that homeowners check the anode rod yearly or every two years. Usually a rod will last for five years, but many factors can change this. The quality of the water and the amount of water used are two major factors. Possibly the most important factor is softened water. Salts in the water create a higher electrochemical reaction and dissolve the anode rod at an accelerated rate.

The anode rod is screwed to the top of the water heater. A homeowner may do the inspection himself, following the instructions in the user's manual, or hire a plumber. If the rod shows exposed steel or has a calcium carbonate covering, the homeowner should replace it. If a corroded rod breaks off in a tank, it will fall to the bottom and may damage the tank's inner walls. This usually drastically shortens the water heater's life.

About Mechanics is dedicated to providing accurate and trustworthy information. We carefully select reputable sources and employ a rigorous fact-checking process to maintain the highest standards. To learn more about our commitment to accuracy, read our editorial process.
Discussion Comments
Share
About Mechanics, in your inbox

Our latest articles, guides, and more, delivered daily.

About Mechanics, in your inbox

Our latest articles, guides, and more, delivered daily.