5 Popular Types of Anode Rod and Why It’s Best for You

What is the reason for having an anode rod? Not all of us know that anode rods or also known as sacrificial rods are very important to water heaters. They were invented or made as its main use is to protect the metal linings inside the water heater from rusting. These rods have layers of metals that attract corrosion toward it and driving it from the other metals inside the water heater. All anode rods have the same necessary purpose but there are only few models in the market.

Before purchasing, it is better for us to get oriented with what these are for and their main purpose. Learn them before proceeding with a replacement of your old anode rod or continuing/starting to maintain your water heater tank.


There are 5 commonly used anode rod in most water heater, these are the following:

  1. Aluminium Anode. This is the traditional type or anode rod and is most likely found in old water heater tanks and old water systems. This is also the main reason why our parents prohibit us to drink tap water, because there was knowledge that this aluminium anode has poisonous effects. This effect has become boundless, however the utility of this anode rod has been lessened nowadays but there are still areas that use this especially the areas where they are using hard water. For you to be able to know if the anode in your water system is aluminium, take one of these rods and bend it, if it will easily bend, then it is aluminium made anode.
  2. Magnesium Anode. One of the popular metals used in anode rod is this type. Magnesium anode is probably the widely used metal for the modern water heaters. One thing that is not an advantage of this type is that it is not very effective to areas where hard water is used. If you are living in a place where there is no water softener, you are utilizing hard water and you are using a magnesium rod for your tank, then check your tank if it has already corroded. Also, do not set a magnesium anode to a rusting tank because this can lead to an electro-mechanical reaction that disperses hydrogen gas that can create a water leak.
  3. Zinc Anode. A rode that is made of a mixture of aluminium and zinc. The proportion will be 1 zinc unit to 10 aluminium units. The power of zinc is it is to serve as a dehumidifier that reduces the smell of the sulphur which affects some of our water tanks. Though, modern heaters are not commonly equipped with zinc anode rods at the factory.
  4. Combination Anode. This is an ordinary anode which is placed in an unusual place. Why? This anode is installed inside the pipe and can be difficult to reach and can involve into a removal or breaking of pipes. This is different compared to other anodes that are attached at the top of the water heater and some are attached to the water heater’s outlet. The unscrewing of the hot water pipe nipple section can also damage the tank. If you want to add a combination anode you can lower the rod into the pipe after you remove the nipple attachment and replace it with a rod.
  5. Impressed Current Rods. A variety of rods that uses electricity to draw the attention of corrosion. They are not the same with the anode rods that was layered with sacrificial metals and the lack of self-created currents which the anode rods are commonly efficient of. Impressed Current Rods does not need to be removed or replaced since they will not corrode, yet they need to be regularly cleaned for it to maintain its electrical charge. They are usually found in commercial water heater systems where rusting is higher than the usual corrosion to the home use water heater systems.

These are the common anode rods that are mostly used and popular in the market. Now, it is for you to decide what to purchase in order for your water heater to be free of rust. For a better understanding, you can contact your plumber and ask for advice on what is the best type for your hot water system.