What Does A Water Heater Anode Rod Do?


What Is a Water Heater Anode Rod?

An anode rod is one of the key components in any water heater tank, running the length of its body from top to bottom. Constructed of metal wire encased by aluminum or magnesium or an alloy made from zinc and aluminum alloys, anode rods play a pivotal role in both efficiency and life expectancy of heating systems as well as in providing essential minerals that make up their supply.

An anode rod is essential in keeping a tank-style water heater anode rod functioning. It connects directly to the top of the tank before being extended outward into the pool below, typically covering between 40-60 inches depending on its dimensions.

Sacrificial anode rods should be changed out at regular intervals. Failing to do this may lead to the creation of sour water or leakage issues within your heater if used regularly and should also provide the opportunity to change out any worn anodes for newer ones with greater longevity. Below is further information regarding its anode.

Anodes Delay the Inevitable

Steel and other metals become vulnerable when exposed to water, since it contains minerals and compounds that attack its metal surfaces. Water tanks made from metal will eventually begin rusting over time and leaking. Therefore, manufacturers use vitrified porcelain coatings on steel tanks in water heaters as a preventive measure against corrosion; although this shield won’t prevent complete protection from rust.

An anode rod provides another means of protecting steel in heating water tanks from corrosion and leaks. Being comprised of lower-quality metals than steel, mineral and substances in water first attack the anode rod before proceeding on their mission against steel; hence their nickname as sacrifices. As long as an anode rod remains unused it will protect from leaks and corrosion in your tank.

Anodes Are Made From 3 Metals

There are two primary kinds of anodes used with water heaters; sacrifice anodes and non-sacrificial anodes are both options; however, certain water conditions require one over the other.


Magnesium rods can be used as screw-in or sacrifice rods that are installed along a cold water supply line, and if your water is acidic the magnesium rod could help reduce scale build-up caused by high alkalinity levels in your tank. Magnesium rods may also help lower chlorine or chloramine levels found within drinking water supplies.

If you begin detecting an unpleasant aroma coming from your water heater, contact a plumbing expert immediately to inspect its anode rod. If they detect clear blue, gray or white beads at the bottom of tanks or on anode rod aluminum anodes can interact with high levels of chlorine in water to produce aluminum hydroxide which should then be converted to magnesium anodes for effective results and reduced beady odor and beads.


Aluminum/zinc anode rods work similarly to their magnesium counterparts when heating water with a sulfate tint. A magnesium anode would convert these sulfates to hydrogen sulfuric acid while an aluminum rod may increase concentration of hydrogen sulfide gas which may result in the distinct smell of rotten eggs being present in hot water.

If your water heater can accept aluminum anodes for its anode rod, your plumber can replace it with magnesium rods in order to alleviate odor problems and restore energy for its tank. In some instances, well shock or plumbing line flushing may also help.


Titanium can be found in non-sacrificial anodes powered by electricity that are fitted into your water tank to protect it. Titanium anodes are more durable than steel and won’t oxidize over time to release unpleasant odors into your tank.

Titanium anodes used in an electronic circuit can only supply a minimal DC current to prevent corrosion in water tanks, with this amount gradually increasing as their integrity deteriorates. Anodes powered by electricity also serve as sensors for low-water levels as well as monitoring integrity; when they reach their maximum DC current capacity they indicate imminent tank failure.

Your plumbers are experts on anode rods that are both non-sacrificial and sacrificeable for use in water heaters. If you detect strange scents or gel-like substances coming from within the unit’s water supply, schedule an inspection of its anodes immediately.

Test your water for rust and minerals using an Water quality Kit. If you detect high concentrations of magnesium, calcium or rust ions in the water supply, please call a plumber immediately in order to change out the anode rod.

Though homeowners can flush and drain their water heater themselves, the replacement of an anode rod requires special plumbing skills, knowledge, and tools for installation. DIYers must remember that improper installation can damage water lines.

Also, if you damage the water heater during installation, its manufacturer could void its warranty. Read through your agreement carefully; many manufacturers will void warranties if installation is performed without the assistance of a licensed plumber and make sure to do your own research prior to purchasing an Anode rod.