If you’re experiencing smelly or rust-colored hot water, you probably need a water heater anode rod replacement. I know, it sounds difficult, right?
Don’t worry. While it might seem complex, it’s actually a quick, easy project for a DIYer with the proper knowledge and instructions. So, let’s get started.
What is an Anode Rod in a Hot Water Heater?
An anode rod is a metal rod the goes down the middle of your water heater’s tank. Its purpose is to minimize rusting to (A) prevent rust from getting into the water supply or (B) shorten the life of your water heater.
The anode rod comes in three different metals: aluminum, magnesium, or an alloy made of aluminum and zinc. Because these metals have a more active voltage than the metal in your tank, corrosion will appear on the rod before it does so on your tank. In a way, the anode rod acts like a decoy (or a magnet) for corrosive sediment in your water heater!
PRO TIP: Only water heaters with a tank require an anode rod. Tankless water heaters do not have them.
Aluminum vs Magnesium Anode Rod
When considering a water heater anode rod replacement, it’s good to know the difference between the two types of materials used.
Either type of rod will work fine in your water heater, and both will last about 5 years before needing replacement. But getting the most out of either material depends on your hard vs soft water situation:
- If you have a higher level of hardness in your water (most parts of the country use hard water), then you should choose an aluminum anode rode.
- If you have soft water (due to a water softener or because you have lower levels of hardness in your area), then a magnesium anode rod will be more effective.
PRO TIP: If the problem you’re having is sulfuric-smelling water (like a rotten egg), then you should consider an aluminum/zinc alloy replacement anode rod. Although these rods contain very little zinc, it is enough to counteract the sulfuric smell.
How Much Does an Anode Rod Cost?
Most homeowners should expect to spend between $20 to $50 for their water heater anode rod replacement.
A lot depends on the model and size needed for your tank, so it’s possible yours might cost more. Also, most water heaters have one rod, but some do have two. There’s little to no difference in price due to the type of material used.
How-to: Water Heater Anode Rod Replacement
Replacing a water heater anode rod is straightforward and won’t take much of your time.
You just need to purchase the correct anode rod (take a photo of your water heater label — with make, model, and size) and head to your hardware store or plumbing supply center. You’ll also need a socket wrench.
1. Removing the Anode Plug
- Close the cold water supply valve and turn the gas control know to off (if it’s a gas heater).
- Since the plug that secures the anode may be rusted to the tank, borrow or rent a 24-inch socket wrench for better leverage.
- Drain 2 to 3 gallons of water from the tank: connect a hose to the drain “spigot” at bottom of tank and place the other end in a floor drain or utility sink. Open the spigot and let it drain out.
- Fit the socket wrench over the anode plug and apply strong, even pressure to turn the ratchet counterclockwise. We recommend that a friend brace the tank, if necessary, while you’re doing this.
2. Replacing the Anode Rod
- Raise the anode rod as far as possible with the socket wrench, then unscrew the last few inches by hand.
- Lift the rod straight up and out of the tank.
- Apply only a single width of pipe tape to the threaded upper end of the new rod.
- Insert the new rod into the tank, screw it in as fast as possible by hand. Then, tighten it clockwise with the socket wrench.
- Open the cold water supply valve and relight the pilot (see Related Resources below).
A water heater anode rod replacement is as easy as buying an anode rod, removing the old one, and putting in the new one.
Of course, there are a few minor but important details in between. But, as you can see, this is a project any homeowner can take on with relative ease and little plumbing knowledge.
- How long does a water heater last?
- A clear guide to the parts of a water heater
- How to maintain and troubleshoot your water heater
- 5 tips for preventing a leaking water heater disaster
- How to relight your water heater pilot light
- Water heater repairs
- How to test your water heater’s T&P valve
- Does your water heater need a water softener?
1-Tom-Plumber’s certified team of plumbers and drain technicians respond immediately to any emergency plumbing, drain cleaning, or water damage problem. We also handle the excavation of underground water lines and sewer main lines. Our immediate-response team is available every day and night of the year, even on holidays.