All About Water Heater Anode Rod

All About Water Heater Anode Rod

A lot of people take their water heater system for granted, often assuming that they can have it installed and just forget all about it. This can be true for the most part. Tank-style water heaters are relatively simple to use and do not require much maintenance. But only if the water heater anode rod is doing fine. Find out more about this water system component.

What Is an Anode Rod and How It Works

The dictionary defines the anode rod as a sacrificial rod that is used mainly in water heaters. The component helps to protect the lining of the water heater and typically prolongs its life. What does that really mean? Plumbing involves water and metals. When these elements combine, you will get something known as galvanic corrosion which is an electrochemical process in which one metal corrodes with another. To prevent the water heater tank from rusting or its heater element from corroding, a sacrificial rod was created long ago by plumbers and chemists to be fitted onto the water heater tank. The idea is to allow the anode rod to corrode first to leave the metal of the tank alone. This is made possible as the anode rod has a lower, more negative electrochemical potential as compared to the steel composition of the water heater. The electrons that are negatively charged produce a higher voltage that flows to the steel tank from the anode rod, corroding the anode rod and not the steel water heater tank.

Checking Anode Rod

You need to first determine where the anode rod is located and how you can remove it. This information can usually be found on your product’s manual sheet. If you have misplaced the manual, just note that anode rods are usually labeled on top of the water heater unit and it is locked in place with a hex nut. It should be easy to pull it out once it has been loosened. For water heater units without a separate hole for the anode rod, you can try searching for it at the hot water outlet.

When to Change Anode Rod

Most anode rods come pre-installed and are made from formed magnesium or aluminum around a stainless-steel cable. When checking for your anode rod, you might see some tiny holes or pitting and that is considered normal. To protect your tank, the anode rod needs to be replaced when a good amount of the cable can be seen. It is not a good idea to wait a long time as having a depleted anode rod can shorten the lifespan of your water heater unit.

Waiting too long may also cause the anode rod to break and fall to the bottom of the water heater unit. This may mean that it will start bouncing around inside the water heater and cause cracks to the glass lining of the water heater unit. This will in turn allow the underlying metal to rust and again, shorten the lifespan of the water heater.