An anode rod is a solid metal cylinder that gets screwed into a water heater’s drain plug to prevent the steel water heater tank from rusting inside. They are made from aluminum, magnesium, or zinc, all metals that will “sacrifice” themselves through electrolysis and save the exposed steel water heater tank from a similar fate.
If you have a Suburban water heater, the tank is porcelain-lined steel and requires an anode rod to prevent corrosion of the steel tank. If you have an Atwood water heater, your water heater tank is aluminum and does not require one.
Important Note: We have read about Atwood water heater owners who have installed anode rods in their drain plugs to prevent the steel threaded drain insert from corroding. This has been reported to be a source of potential leaks as the steel drain insert can eventually rust.
Check The Anode Rod At Least Once A Year
If you have a Suburban water heater, it’s important to check the anode rod when you’re inspecting your water heater. Failure to replace it will result in premature tank wear, possibly lead to a messy tank leak, and can void the warranty.
When an anode rod has lost approximately 75% of it’s original mass, it is time to replace the anode rod. Fortunately, anode rods are relatively inexpensive, usually last a couple years, and are easy to replace.
When we checked, our anode rod had about 50% of it’s original mass. To be on the safe side, we replaced it with a new one.
TCM reader, Rex Carroll, sent in a picture of his rod, which was down to the metal core. This rod was no longer protecting the water heater tank.