How To Replace Your Water Heater’s Anode Rod

by Trevor Woods | Last Updated: May 26, 2020

Nothing is worse than showering in rusty water or having to replace your water heater years before its life expectancy is over. This costly and unpleasant experience can be avoided by simply checking your hot water tank’s anode rod and replacing it when necessary.

Our tutorial will show you how to easily check and replace your water heater’s anode rod in a few simple steps.

What Is An Anode Rod?

The anode rod in your water heater is a special metal component that’s meant to slowly dissolve so that the tank itself doesn’t corrode. This anode rod is typically made up of magnesium, aluminum, and zinc which corrode preferentially to the inside walls of your water heater.

Since these rods protect against galvanic corrosion by sacrificing themselves first they are also called galvanic anodes or sacrificial anodes. You can find these sacrificial anode rods in the plumbing world and in bridges, pipelines, and marine applications like boat hulls. 

When your water heater’s anode rod is depleted, it no longer offers corrosion protection for the tank. To avoid damaging your water heater it’s best to replace the sacrificial rod before that happens. 

Aluminum Anode Rod

$27.51

The anode rod is a sacrificial rod that extends the life of your water heater tank by absorbing the corrosion causing particles in the water.

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12/18/2023 08:15 am GMT

How Often Do You Need To Change Anode Rods?

You should change your sacrificial anode rod a minimum of once every 4 to 5 years. But if you notice that your hot water is brown or rusty in color that means the tank itself is starting to corrode and the anode rod needs to be replaced immediately. If you fail to fix this issue quickly the corrosion will progress to the hot water tank and potentially causing premature leaks.

We recommend that you start checking your anode rod every year. The ideal time to inspect your sacrificial rod is when you flush your water heater as part of your annual maintenance plan.

When you inspect your anode rod for cathodic breakdown you should be checking to see how much of the sacrificial anode rod remains. Once it looks like the rod is 75% depleted and only 25% of its mass remains, it’s time for a new rod.

Checking and changing your anode rod is a great way to extend the life of your water heater and avoid having to replace your hot water tank prematurely.

What Type Of Anode Rod Do You Need?

Both electric and gas water heaters use the same anode rods. And you can find sacrificial anode rods in various lengths. When in doubt, purchase a longer anode rod, it can always be cut down later to the correct length.

If you notice that you have smelly hot water, it could be a result of how the water is reacting to your water heater’s anode rod. If you experience a “rotten egg” smell you should consider replacing your anode with one made of aluminum and zinc to combat unpleasant hot water odors.

Aluminum And Zinc Flexible Anode Rod

If you have smelly hot water this rod is for you!!

The zinc in this anode rod is designed to combat odor that comes from your hot water tank.

Zinc counteracts this natural process and eliminates unwanted odor. 

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A better option for smelly water would be to get a powered anode rod. These sacrificial rods provide superior corrosion resistance, improve water quality, last longer than standard anode rods, and will eliminate hot water odors.

Powered Titanium Anode Rod

$21.99 ($0.69 / Fl Oz)

Say goodbye to odors!

Eliminate your water heat odor problem by removing the rotten egg smell caused by hydrogen sulfide with our advanced powered anode rod.

Permanent corrosion protection and can help defend against any level of water hardness.

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02/17/2024 11:30 am GMT

If your water heater is tucked away in a tight location and there is not much room overhead to slide in a solid anode rod you will need a flexible anode rod for your replacement.

Flexible Anode Rod Kit

$439.99

Everything you need in an all-in-one kit!

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02/17/2024 10:51 am GMT

Can’t Find Your Anode Rod?

If you are unable to locate your sacrificial anode rod, consult your water heater’s Owners’ Manual. You may have a combination hot water outlet and anode rod.

How To

This guide will give you a detailed step-by-step procedure for how to replace an anode rod on a gas or electric hot water heater.

Before you start this repair, please thoroughly read the Use and Care Manual provided with your water heater. If at any time you are unsure or uncomfortable about changing your anode rod don’t hesitate to stop and call a professional for help.

Tools And Materials Needed

• Replacement Anode Rod or Anode Rod Kit
• Rag

Water Heater Element And Anode Wrench

$9.99

This wrench socket has one end sized 1-1/2" for water heater elements and the other end sized 1-1/16" for anode rods.

Allowing you to maintain your water heater without any additional tools!

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12/18/2023 04:53 am GMT

1. Turn Off Your Water Heater

First, turn the power off to your water heater at the circuit breaker for electric water heaters or for gas hot water tanks you should turn off the gas supply. You can do this at the water heater’s gas control valve located near the bottom of the tank.

2. Drain The Hot Water Tank

Now you can close the shutoff valve at the cold water inlet line. Open a nearby hot water faucet to relieve system pressure and allow the tank to drain properly.

Attach a length of garden hose to the drain valve at the bottom of the hot water tank and run the other end of the hose to the nearest floor drain or outside the home where it is safe to drain. 

Take your flat blade screwdriver and open the water heater drain valve. You’ll want to drain approximately 2 gallons of water from the tank. This should be enough to bring the water level low enough to avoid water spilling out the top when you unscrew the old anode rod.

Don’t Drain The Water Heater Entirely

The weight of the water inside the tank will help stabilize the tank while you break loose the old anode rod.

3. Remove The Old Anode Rod

Locate the anode rod‘s location on the top side of the tank. Usually, sacrificial anode rods are covered by a plastic cap on new models but are clearly visible on some water heaters.

Remove the plastic cap to expose the anode rod if it’s not clearly visible. If the sacrificial anode rod is covered in foam insulation take a flat blade screwdriver and carefully remove the insulation.

Using a 1-1/16″ Socket and breaker bar, remove the anode rod by turning it counterclockwise. Have a rag handy because there will be some water seep out from around the anode rod for location. 

Cool Tools!

If you have an impact driver handy, you can use it to break the threads loose instead of using a wrench or cheater bar. 

Be careful as you remove the old anode rod. It will be hot from the water inside the tank. And try not to knock any corrosion or pieces of the sacrificial rod off inside the tank as you slide it out of the water heater.

The anode rod will show signs of deterioration and will look like it is dissolving.

4. Prepare The Replacement Anode Rod

Now that you have the old anode rod out you can get the replacement sacrificial rod ready to be installed. Compare the length of the old rod with the new one. If needed, cut the replacement anode rod down to a similar length with a hacksaw. Then you can use a file to smooth the cut edge before you install the rod.

Wrap the threads of the new sacrificial rod with several wraps of Teflon tape or pipe-joint compound. 

5. Install The New Anode Rod

Seat the new anode rod in place and turn it clockwise. Be careful not to cross-thread the connection. Tighten the new anode rod tightly with your socket and wrench. 

6. Refill The Hot Water Tank

Once the new anode rod is installed, turn the cold water supply to the water heater back on and fill the hot water tank. Once the water starts to flow steadily from the faucet you opened earlier you can turn that faucet off.

With the tank full of water check around the new sacrificial anode rod for any leaks. If there are no dribbles or drips, replace the plastic cap to cover the head of the anode rod.

7. Turn The Water Heater Back On

Now you can turn the water heater back on. Switch the power back on at the circuit breaker if your water heater is electric and turn the fuel supply back on for gas-powered tanks. You may need to relight the pilot of your water heater. Follow the instructions printed on the outside of the water heater or the tutorial we created here.

After the water heater is back up to operating temperature recheck the anode rod for any leaks. Water expands as it is heated and it’s best to confirm the anode rod seal is tight enough to handle this increase in pressure. Check the anode rod one more time in 24 hours and retighten if necessary. Done!

Conclusion

You may not be as young as you once were but you’ve just added years of life to your water heater by replacing the hot water tank’s anode rod! Checking the sacrificial anode rod every year and replacing it when necessary will improve your water quality and greatly extend the lifespan of your water heater. Oh to be young again!

Happy Plumbing!

Trevor Woods is the founder of Plumb University® and he started in the plumbing and construction industry in 1997. Since then, his mission is to make plumbing repair and maintenance easy for everyone. And each year, he continues to help more people with their plumbing installation, care, and troubleshooting.