Rust and other types of corrosion are the worst problems a water heater can face. When rust starts to develop on a water heater tank, that usually means the entire water heater must be replaced.
But if you care for your water heater properly with regular professional maintenance and repairs done as needed, you shouldn’t have to worry about corrosion until the system is reaching the end of its lengthy service life. Most of the thanks for that protection against rust and corrosion goes to a component called the anode rod. We’re going to focus on this part of your water heater today, because understanding it will help you remember why regular maintenance for a water heater is so critical.
The Anode Rod Defends Against Corrosion
The anode rod is a long metal rod inserted into the top of the water heater tank that extends down through the tank. The job of this rod is to stop corrosion from affecting the tank. Corrosion occurs when metal and water are in contact in the presence of oxygen. A water heater already has some defenses against corrosion, such as a glass lining in the tank and methods to keep oxygen from getting inside. But the anode rod provides the most effective prevention.
Essentially, the anode rod attracts corrosion to itself so it doesn’t affect the rest of the water heater. It corrodes so the rest of the water heater doesn’t. This is why the anode rod is sometimes called a “sacrificial” anode rod. Sounds a bit dramatic, but it does literally sacrifice itself to corrosion so the rest of the system can enjoy a longer service life.
How the Anode Rod Does This
The anode rod isn’t made from a single type of metal but from two. With most anode rods, this is magnesium or aluminum wrapped around a core of steel. The contact of these two different metals causes a process called electrolysis. This attracts the ions that cause corrosion, so they move away from the other parts of the tank and instead cause the rod to corrode.
Replacing the Anode Rod
What happens when the anode rod completely corrodes? It will no longer protect the rest of the water heater. And this is why regular maintenance is so important: the anode rod must be changed at regular intervals when it corrodes all the way through. Each year during professional maintenance for your water heater, one of our technicians will check the anode rod to see if it’s time to replace it and then replace it if necessary.
Regular maintenance helps prevent corrosion in other ways as well, such as flushing the tank and catching leaks that can allow oxygen into the tank. You can trust our professionals to keep your water heater in great shape. We work with all types of water heaters in central Indiana and we know what yours needs to keep working for your household for many years to come. Contact us at a location near you.