Sacrificial Anodes for Water Heater

The hot water heater is a crucial element of running a home that often performs without notice. That is, until it stops or begins to make funny little noises. Due to homeowners being basically inattentive to them they go far too long without proper maintenance.

Lots of people simply wait for their hot water heater to start making these funny noises before taking any action. At that time they believe it is time to replace it. This is great for shady salesmen but that doesn’t make it true. It can be sediment buildup causing the hot water heater to make those noises.


Sediment buildup happens over time as minerals that occur naturally in your water build up causing the deterioration of the sacrificial anode.

In hot water heater terms the ‘sacrificial anode’ is a metal rod designed to corrode gradually over time. It can be made from aluminum, magnesium, or an aluminum/zinc combination. The water within your tank will set off an electrolytic reaction causing the exposed steel to fail. In order to protect the steel a magnesium or aluminum rod that is more reactive will corrode in its place. Once this anode has corroded then the steel within the tank will start corroding itself. Then your tank is headed toward failure.



Common sense dictates that if you replace this anode regularly then the steel within your tank will stay protected. Usually they need replacing around every 3 to 5 years. This prolongs the life of your hot water heater.

The sacrificial anodes work by being screwed directly into your tank usually near the top. That way they are more easily replaced. They are quite long and require substantial room for clearance when removing them from your tank.

It will depend on what type of anode you get as to how often it will need replaced. Some are more expensive than others but will not corrode as quickly. Many people warn against the aluminum anodes. They are cheaper but come with a whole other set of problems like breaking or contaminating your water.

There are some tanks that utilize 2 anodes. They will have the conventional anode placed at the top and also an outlet anode either at the top as well or down at the bottom of the tank. They should be replaced together simultaneously and the same metal types should be used.

They should never be mixed or matched separately. Regular replacement of your sacrificial anodes can get you many more years of use from your hot water heater without having to replace it. Some good information can be found at online.

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