In this article, we’re examining an important yet oft-forgotten component of you water heater – the water heater anode rod. The anode rod plays a crucial role in prolonging the life of a water heater, but it requires occasional maintenance and replacement. We’re going to tell you how often you need to replace this rod to keep your water heater in working order, and how to do it properly.
How often should you change the anode rod in a hot water heater?
The most accurate answer to this question is “whenever the rod becomes so corroded that it no longer works” (more on this below). Unfortunately, since the anode rod is located inside your water heater, you won’t always know when that is.
We recommend checking your anode rod yearly. Generally speaking, you’ll need to replace it every 3-5 years, but it depends how much water runs through your water heater on a regular basis, and the number of corrosive materials present in said water. Next, we’ll show you how to check if your rod needs to be replaced, and how to do it.

How to Change Anode Rod in Water Heater
Now that we know how often we need to change an anode rod, an important question remains – how do I do it? To properly understand this process, let’s first examine what an anode rod actually does, which will help you know whether it has “gone bad.”
First: What is an Anode Rod
A water heater tank is generally made from steel or another metal. Steel is a material which rusts, especially when repeatedly exposed to water. An anode rod is a long rod that is screwed into the top of a water heater and works to attract the corrosive elements of the water away from the side of the tank.
Related: Rheem Water Heater – Ultimate Troubleshooting Guide
These corrosive elements will be drawn to the steel anode rod instead of the tank itself, preventing rust. Essentially, the anode rod is “sacrificing” itself, and is often called a “sacrificial anode rod.” The reason this works is because the anode rod has a more negative electrochemical build than the tank itself.
What Happens When Your Anode Rod Goes Bad?
By drawing the corrosive elements of the water toward the rod, the anode rod itself begins to rust. Past a certain point, the metal in the rod will rust to a point where it no longer has any metal left to perform its “sacrificial attraction.” At this point, the rod has gone bad, and the corrosive water might cause the tank to rust. At worst, it might even cause the tank to burst.
How Do I Know if My Anode Rod isn’t Working?
One of the biggest signs that your anode rod is no longer working is when your hot water becomes smelly or discolored. This is because the anode rod is no longer protecting your tank from rust and corrosion, and it ends up in your tap water.
This is also why you need to check your anode rod roughly once a year to see whether it has corroded to the point where it is no longer useful. If your rod is almost fully corroded, or has started to break loose, then it is time for a replacement. Below, we’ll give you a walkthrough for accessing and removing your anode rod, and replacing it with a new rod (if necessary).

How to Change an Anode Rod
Step 1 – Beginning Considerations
Before we get started, it’s important to note that this is a general guide. You need to check your specific hot water heater to see whether it requires a specific brand, material, or model of anode rod. First and foremost, consult your device’s user guide to see whether there are specific considerations you must follow.
Step 2 – Power and Water
Now we’re getting started. First, you need to shut off the power to your water heater. This means shutting off the thermostat for a gas water heater or turning off the breaker for an electric unit. Additionally, turn off the water supply line on the unit or turn off the water directly at the pump.
Step 3 – Drain Water Heater
Since we’re working with the interior components of the water heater, it will need to be partly drained beforehand.
Locate the drain at the bottom of your water heater. You need to attach a hose to the drain and bring the hose to a suitable drain or an outdoor location. Open the drain valve and a close-by hot water valve (i.e., a hot water source close to the heater), and drain about 15% of the tank. If the tank is still hot, you need to let it cool off before removing the rod.
Step 4 – Locate and Remove
Consult your device’s user manual to locate the anode rod. It’s almost always accessible from the top side of the water heater, where it is screwed into the device.
Most of the time, you can simply unscrew the anode rod with a socket (with a breaker bar) or a wrench. If the rod is particularly stuck, ask someone to hold the tank in place so that it doesn’t twist as you twist the rod.
The rod should come out rather easily, but it might take some elbow grease.
Step 5 – Install New Rod
If the rod is breaking apart, or just about fully corroded, then you’ll need to replace it with a new rod. Once again, be sure that you buy a rod that is designed for use with your water heater. Rods may be made from aluminum or magnesium, which are often interchangeable, but it’s best to be sure.
Once you have a new aluminum anode rod or a magnesium anode rod, installing it will be easy. The process is the reverse of how you removed it. Be sure that you tighten the new rod into place extremely securely, using your socket or wrench to finish the job.
Then, close the drain on the water heater, and turn the water supply back on. Open the hot water valve as the tank refills with water until the tank is completely full. Finally, turn back on the power (if electric) or the thermostat (if gas).
And there you have it, a brand-new sacrificial rod to keep your tank safe!