How To Change a Water Heater Anode Rod

One often overlooked component in a water heater is the anode rod, which plays a vital role in protecting your water heater from corrosion.

In this guide, we’ll walk you through the process of changing a water heater anode rod, a task that can significantly extend the life of your appliance. In the video above, This Old House plumbing and heating expert, Richard Trethewey, demonstrates the steps involved in replacing this critical component for electric water heater but this process is also important for a heat pump water heater or other type of tank water heater.

Understanding the Anode Rod

The anode rod is a key player in your water heater’s defense against corrosion. By design, the anode sacrifices itself to protect the tank’s steel lining.

What Is an Anode Rod?

An anode rod is a long metal rod typically made of magnesium, aluminum, or zinc. It’s inserted into the water heater tank and acts as a sacrificial element, attracting corrosive elements in the water that would otherwise attack the tank’s steel lining.

Why Is It Important?

The anode rod’s primary function is to extend the life of your water heater. As Trethewey explains, water naturally wants to attack steel. The anode rod, which uses a less noble metal, becomes the primary target for this corrosion and, in effect, protects the tank.

When To Replace the Anode Rod

Typically, you should inspect your anode rod every three to five years and replace it when it’s significantly corroded.

If more than 6 inches of the core wire is visible or the rod is less than 1/2 inch thick, it’s time to replace it.

Preparing for Water Heater Anode Rod Replacement

Before you begin the replacement process, you’ll need to gather the necessary tools and materials and take proper safety precautions.

Tools and Materials Needed

• Garden hose
• New anode rod
• Ratchet wrench with 1 1/16-inch deep socket
• Screwdriver
• Steel pipe (for extra leverage if needed)
• Teflon tape

Safety Precautions

1. Turn off the water supply to the water heater.
2. Shut off the fuel supply (gas or electricity) to the water heater.
3. Allow the water in the tank to cool before proceeding.

Steps To Change the Anode Rod

Changing the anode rod involves several steps. Follow these carefully to ensure a successful replacement.

Locating the Anode Rod

1. Look for the anode rod on top of the water heater.
2. In some models, you may need to remove a cover to access it.
3. The anode rod typically has a hexagonal head.

Draining the Tank Partially

1. Connect a garden hose to the drain valve at the bottom of the tank.
2. Open the valve and drain the water until it’s just below the level of the anode rod.
3. This partial draining helps maintain weight in the tank for stability during rod removal.

Removing the Old Anode Rod

1. Use a ratchet wrench with a 1 1/16-inch deep socket to unscrew the anode rod.
2. If the rod is stuck, use a steel pipe on the wrench handle for extra leverage.
3. Be prepared for resistance, as Tretheway demonstrates.
4. We recommend having at least two people perform the rod removal—one to hold the tank and one to unscrew the old rod. Depending on how stubborn the rod is, you may need to apply more leverage. 

Installing the New Anode Rod

1. Wrap Teflon tape around the threads of the new anode rod.
2. Carefully insert the new rod into the water heater.
3. Tighten it securely using the 1 1/16-inch socket.

Changing a Water Heater Anode Rod: Dealing with Limited Space

In many homes, water heaters are installed in tight spaces, making it challenging to replace a standard anode rod. Understanding your options can make the replacement process more manageable.

Using a Collapsible Anode Rod

If you have limited clearance above your water heater, consider using a collapsible anode rod. These rods are designed like links of sausage, allowing for easier installation in confined spaces. This innovative design can be instrumental in maintaining water heaters found in tight basements or closets.

Alternative Installation Methods

1. If space is minimal, you may need to tilt the water heater slightly.
2. In some cases, you might need to disconnect water lines to create more room.
3. Always consult a professional if you’re unsure about the best approach.

Changing Anode Rod in Water Heater: Finishing Up

After successfully installing the new anode rod, there are a few final steps to complete the process.

Refilling and Restarting

1. Close the drain valve and remove the garden hose.
2. Turn the water supply back on and allow the tank to refill.
3. Open a hot water faucet in your home to release any trapped air.

Checking for Leaks

1. Inspect the area around the new anode rod for any signs of leakage.
2. Tighten the rod further if you notice any drips, or reapply Teflon tape.

Restoring Power

1. Once you’re confident there are no leaks, restore the fuel supply to the water heater.
2. For electric heaters, switch the circuit breaker back on.
3. For gas heaters, relight the pilot light following the manufacturer’s instructions.

Common Challenges and How To Overcome Them

Replacing an anode rod isn’t always straightforward. Here are some common issues you might face and tips for handling them.

Stubborn Anode Rods

Over time, the formation of corrosion can make it quite tricky to remove an anode rod. If you encounter a stuck rod, consider using a longer wrench or a piece of steel pipe to gain additional leverage. Applying penetrating oil around the rod’s threads may also help break the corrosion seal.

Limited Clearance

As discussed earlier, limited clearance above your water heater can pose a significant challenge. Collapsible anode rods or segmented rods are practical solutions, fitting easily into tight spaces without extensive maneuvering.

Maintaining Your Water Heater

Regular maintenance can significantly extend the life of your water heater and improve its efficiency.

Regular Inspections

1. Check the anode rod annually, especially in areas with hard water.
2. Inspect for signs of rust or sediment buildup in the tank.
3. Test the pressure relief valve periodically to ensure proper function.

Flushing the Tank

1. Drain and flush your water heater tank annually to remove sediment.
2. This process can improve heating efficiency and extend the life of your appliance.

Professional Maintenance

Consider having a professional plumber inspect your water heater every few years. They can perform more thorough maintenance and catch potential issues early.

Changing the Anode Rod in Water Heater: Our Conclusion

Changing your water heater’s anode rod is a simple yet effective way to extend its lifespan. While it may require some effort, especially in tight spaces, the benefits far outweigh the inconvenience. Regular maintenance, including timely anode rod replacement, can save you money and ensure a reliable hot water supply.

Shopping list:

• Anode rod
• Steel pipe, used to provide extra leverage to ratchet wrench
• Teflon tape
• Garden hose, used to partially drain the water heater

Tools: