Anode rod close-up showing corrosion
Learn how anode rods prevent water heater rust.

If you had to name the most important home comfort appliance in your home, what would it be? If you said your water heater, you’re right. Your water heater works hard day in and day out to provide you with the hot water you need to shower, bathe, wash dishes, do the laundry, and so much more. So of course, you want to keep this trusty appliance working properly for years on end. And there’s one component that can make that happen – the anode rod.

What Is an Anode Rod?

A water heater’s anode rod (or sacrificial rod) is a metal rod that runs down a tank-style water heater’s center. Usually made from aluminum, magnesium, or zinc, and wrapped around a steel wire core, an anode rod’s primary purpose is to protect the inside of the water heater tank from rust and corrosion. In short, the rod sacrifices itself to preserve the water heater.

What Does an Anode Rod Do?

The heat and minerals in a water heater’s metal storage tank may cause it to rust over time. The anode rod prevents the water heater tank from premature corrosion by protecting it from the corrosive elements present in water. The metal in the anode rod uses electrolysis to attract harmful particles like sediments and minerals responsible for corrosion. The idea is that the anode rod would corrode first, leaving the metal of the tank (and element if you have an electric water heater) alone, saving you from dealing with a rusty tank that randomly springs leaks.

Types of Anode Rods

The most common type of anode rod is a magnesium anode rod. As it corrodes more easily, magnesium is a more suitable material for a home with soft water. Aluminum anode rods work better for homes with high pH and hard water. Zinc and aluminum blend rods are suitable for homes where the water is sulfurous in odor. They contain only 10% zinc, which helps prevent the rotten egg-like smell.

When to Change the Anode Rod

As the anode rod wears down, it becomes essential to inspect it regularly and replace it when necessary to prevent severe damage to the tank and avoid costly repair. To keep protecting your tank, the anode rod must be replaced when a good chunk of the cable becomes visible. Waiting too long will shorten the life of your water heater.

Typically, anode rods have a life expectancy of about three to five years. However, several factors can reduce or extend the life of an anode rod. These include: water quality, pH level of water, household hot water usage, and water heater maintenance.

Change your anode rod right away if you notice any of the following:

  • The water heater makes popping noises when heating up.
  • The water heater is more than 5 years old and you’ve never changed the anode rod before.
  • You notice a slimy gel substance when cleaning out faucet aerators.
  • Your hot water has a rotten egg odor.
  • Your hot water has a rusty or brown color.
  • The water heater is leaking.

Whether you’ve encountered problems related to the anode rod or other issues affecting your water heater, we at Zach Heating & Cooling are ready to help. From service and repair, to new water heater installation – including tankless – you can count on Zach to make all your hot water troubles disappear.