Guide and tips

The sacrificial anode: what is it and when should you replace it?

The sacrificial anode is an essential component of your water heater. It’s a long metal rod, made of magnesium or aluminum, which extends through the tank’s interior.


It attracts particles of iron, limestone or other minerals present in the water through an electrochemical process and corrodes in place of the tank. In other words, it “sacrifices” itself to extend the life of the water heater.

Most water heater manufacturers will recommend inspecting the condition of the sacrificial anode every one (1) to three (3) years and replacing it when it has been consumed more than 50%. This is especially true if you have hard water or use a water softener.

Careful though! In some cases, replacing your water heater’s anode rod yourself could void the appliance’s warranty. Check the terms of your warranty or consult your supplier before undertaking this operation.

Where can you find a new anode for your water heater?

You can easily find replacement anode rods for standard water heater models in hardware stores or superstores. Aluminum anode rods are the most common type and their average price varies from $20 to $40. Make sure you note down your water heater model and tank size (in gallons) before buying the anode rod.

A special order will probably be required for compact water heaters or those that exceed 60 gallons.

How do you check the condition of the sacrificial anode?

  1. Since the sacrificial anode is immersed in the tank, you’ll have to drain the water heater to check its condition.
  2. Depending on the model, you’ll either have to drain it partially or empty the water heater completely. Make sure you know how to carry out the draining process before you begin. Then, follow these steps:
  3. First, turn off the power to your water heater.
  4. Consult the manufacturer’s manual to locate the anode rod. Its location depends on your water heater model. Most are accessible from the top of the appliance, hidden under a plastic cap. You may have to remove insulating material to reach it.
  5. Now drain the tank, at least partially.
  6. Remove the corroded anode rod with a 1 1/16-inch socket wrench. Wearing work gloves is recommended for this step since the rod might be hot. You should expect some resistance at first before the worn-out anode gets freed.
  7. Install the new anode and restart your water heater by completing the draining process.

If you have questions or concerns regarding the replacement of your sacrificial anode, contact us. We’re here to help!

GIANT Inc., Residential Water Heater: Owner’s Manuel – Installation and Operating Instructions (p.10)