All About Your Tank-Style Water Heater Anode Rod

If you have a tank-style water heater, then you should learn about an important tank component called the anode rod. This rod attracts the corrosive elements in your home's water before they come into contact with your metal tank to prevent tank corrosion. By choosing the right anode rod and having it replaced on a regular basis, you can extend the lifespan of your hot water heater tank.

Read on to learn more about water heater anode rods, including the different types on the market today, common anode rod problems, and how often you should replace your rod.

Anode Rod Types

Several anode rod types are available today. Some common ones include:

Aluminum rods. Anode rods made from aluminum work well in homes with hard water. However, since these rods can leach aluminum into your home water supply, you should not drink hot water straight from the tap when your tank is equipped with an aluminum rod.
Magnesium rods. Magnesium rods are common today and work well in homes with relatively soft water. While these rods can be used in homes with hard water, they corrode more quickly in this water type leading to the need for more frequent replacement.
Zinc rods. Zinc anode rods are made from both aluminum and zinc. This rod style is typically only recommended when hot water in a home smells like sulfur or rotten eggs because the small amount of zinc in these rods helps counteract this smell.
Impressed current rods. These rods attract corrosive water elements with electricity and typically last the life of the hot water tank without the need for replacement. This anode rod style is much more common in commercial water heaters than those used in homes.

While most anode rods are attached to the tank lid and run vertically through the center of the hot water tank, some are instead located inside the tank’s hot water outlet.

Common Anode Rod Problems

While most anode rods perform their jobs efficiently and simply need to be checked for corrosion and replaced on a regular basis, others can develop problems.

One anode rod problem that can occur when a home has hard water is calcium carbonate buildup. This calcium layer causes your anode rod to repel corrosive elements in the tank water instead of attracting them, reducing tank corrosion protection. If a plumber finds calcium buildup on an anode rod, they can often simply remove this layer instead of replacing the rod.

Another anode rod problem is passivisation of the rod. This problem occurs when a rod stops performing the chemical reaction with the surrounding water that is needed to attract corrosive water elements or never begins performing this chemical reaction after installation.

The most frequent sign of anode rod passivisation is lack of rod corrosion after it has been in place for several months or longer. The only solution to this problem is to replace the current non-functional rod with a replacement rod.

Routine Rod Replacement

The lifespan of a hot water heater anode rod depends on many factors, including the rod type, your water hardness, and how much hot water your family uses. While some anode rods can last five years before replacement is needed, others, such as those in homes with over-softened water, can completely corrode in just six months.

For this reason, you should have your anode rod examined for corrosion by a licensed plumber every year. Your plumber will check its current corrosion level and determine if it needs immediate replacement or is likely to last another year before replacement is needed.

However, you should have your anode rod replaced immediately if it has already been in place for five years; if a slimy gel is accumulating on your faucet aerators, which means that your aluminum rod is leaching large amounts of aluminum oxide into your home water; or if your water heater is making popping noises.

When you have your hot water heater anode rod inspected and replaced on a regular basis, you can prevent tank corrosion to increase the lifespan of your hot water heater.

Contact the water heater experts at Water Heater Pros to schedule hot water heater anode inspection or replacement today.