What is an Anode Rod?


An anode rod (also called a sacrificial anode rod) is a metal rod in your water heater that is typically coated in magnesium, zinc, or aluminum. The purpose of the anode rod is to protect the metal lining of your water heater tank from corrosion and rust.

How does an anode rod work?

Anode rods were designed to slow down corrosion and rusting that occurs in water heaters. The rust and corrosion occurs due to the metal from the water heater coming into contact with moisture and oxygen (i.e. oxidation). In addition, the corrosion process speeds up due to the constant heating within the water heaters. In order to combat the rust and corrosion effects, the coated anode rod will interact with the oxygen instead of the tank, which in turn causes the anode rod to corrode in place of the water heater.

What are the different types of anode rods?

There are three main types of anode rods:

  • Magnesium anode rods – These anode rods are the most common type you’ll find in water heaters. They work best in places that use soft water, although they can be used in places with hard water. Using the, in hard water locations will reduce their lifespan.
  • Aluminum anode rods – designed to work best in places with hard water, and is able to handle hard water much better than magnesium anode rods.
  • Zinc anode rods – In addition to preventing corrosion from affecting the water tank, zinc anode rods reduce Sulphur smells that may be present.

How do I know if my anode rod is bad?

If you notice discolored or odorous hot water in your water heater tank, then your anode rod is likely bad and will need to be replaced.

How often does an anode rod need to be changed?

Anode rods will need to be changed every 3 to 5 years on average. It is advised you get a plumber or specialist to inspect your water heater tank to determine if your anode rod needs to be replaced.

How much does it cost to replace an anode rod?

Anode rods typically cost around $30-$40 , and that would be all you have to spend if you were replacing it yourself. If you are looking to have a professional replace the anode rod, the cost will be around $200 – $300.

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