Plumbing, Water Heaters

Water Heater Leaking From Anode Rod

water heater top leaking 2 lg

Any signs of a leak from your water heater are sure to cause you stress. However, leaks coming from the top of the water heater are easily fixable if caught early. Often the leaks come from loose fittings and require minimal attention. If you check all the fittings and if your water heater is leaking from the top of the tank, the culprit is may the anode rod. 

Also known as the sacrificial rod, the anode rod in a water heater attracts and removes contaminants from the water. Over time, the anode rod in your water heater will begin to break down, and you need to replace it. If not replaced in time, the fitting around the anode rod can start to leak water.

The anode rod is designed to help make your water heater last for decades. Checking the condition of the anode rod should be included in the regular maintenance of your water heater. This article will help explain the critical role of the anode rod, how you can know when it needs to be replaced, and when to call a plumber.

Why Is Your Water Heater’s Anode Rod Leaking?

The anode rod, also called a “sacrificial rod,” is a rod inside the water heater tank made of aluminum, magnesium, or other alloy metals that create a chemical reaction called electrolysis. That word may conjure up images of women in beauty salons having unwanted facial hair removed. The process for hair removal is similar to what happens in your water heater.

The anode rod creates an electrical current that attracts corrosive materials in the water to itself and away from the tank’s lining. Over time, the anode rod will disintegrate, sacrificing itself to save your water heater tank. The anode rod fitting will begin to leak if the corrosion is extensive or if the rod has disintegrated completely. 

If water is leaking only around the anode rod fitting, you may be able to check the rod yourself to see if a new one is needed. Contact your local plumber if you do not have the necessary tools or prefer to have a professional service the water heater.

How to Replace a Water Heater Anode Rod

Depending on the water heater you have, it is possible to check and replace the anode rod yourself. Be aware that this is a dangerous job and can cause serious injury if not done correctly. 

1. Turn Off the Power

Turn off the power supply for the water heater, whether it’s gas or electric. 

2. Turn Off Water

Close the cold water shutoff valve located on top of the water heater.

Some water heaters, such as the Bradford White, have an anode rod located in the hot water outlet. In this case, you will also need to close off the hot water valve.

3. Open Hot Water Tap

Open the hot water tap in a sink will allow pressure to equalize inside the tank. You don’t want your water heater turning into a rocket.

4. Drain Water

water heater drain valve

Connect a garden hose to the drain valve located at the bottom of the water heater. Using a flathead screwdriver, open the valve to release water. 

Drain off 2 to 5 gallons of water. DO NOT DRAIN THE WATER HEATER COMPLETELY! The water draining from the tank will be extremely hot and can cause burns. Once you have drained the water, close the drain valve and remove the hose. 

Carefully examine the water for any signs of rust or sediment. These are good indicators the anode rod has disintegrated.

5. Locate And Loosen The Anode Rod

The anode rod fitting is located on top of the water heater. The threaded fitting will either be sitting on the outside of the tank or located under a rubber cap you will need to peel away.

If your water heater is older and has rusty fittings, do not use any solvents to loosen the rust. These chemicals could make their way into your water heater, contaminating the water. If there is extensive rust or you are having difficulty removing the fitting, it may be best to call a professional who will have the needed tools to do the job safely.

Once you have located the anode rod fitting, you will use a socket wrench that fits the size of the fitting. Turning in a counter-clockwise motion, carefully loosen the fitting. Be prepared for some water to come out of the opening fitting loosens.

6. Remove Anode Rod

Carefully remove the anode rod by lifting it straight up. The rod will be very hot and very fragile. It can break apart further if not handled gently. Anything that falls into the tank will need to be flushed out. 

7. Inspect Anode Rod

If you see signs of pitting or disintegrating, this is good. This means the anode rod has been doing its job. Deep pits or missing sections altogether mean a new anode rod is needed right away. If you see no signs of corrosion, replace the rod immediately! You have a defective rod. 

8. Install New Anode Rod

Prepare the threads on the replacement anode rod by wrapping it five or six turns with Teflon tape. Carefully insert the new rod into the tank, tightening the fitting with a wrench.

9. Refill The Tank

Open the cold-water supply valve and refill the tank. When hot water starts coming out of the hot water faucet you opened earlier, this means the water heater tank is full. Your faucet may have air in the line initially, but this will go away within a few seconds. 

10. Inspect Your Work

Inspect the anode rod fitting and cold-water inlet valve to make sure there are no new leaks. If you are leak-free, you can restore power to the water heater. 

If you feel overwhelmed after reading through the steps of replacing the anode rod yourself, there is no shame in calling a professional. Your local plumber will be happy to come out and service your water heater.

How Do You Know If Your Anode Rod Is Bad?

Because the anode rod is inside the water heater, it is not always easy to know the condition of the anode rod until there are outward signs. If detected early enough, some signs indicate that the anode rod is working but may need some attention. Other signs, if left unchecked, could spell serious disaster.

Signs that the anode rod in your water heater is bad includes:

  • Water that smells like rotten eggs
  • The water has a metallic taste
  • The presence of foam or discoloration in the water
  • Water heater makes noises as it begins to heat up
  • Leaks on the top of the water heater where the anode rod fitting is

Water leaks due to a bad anode rod are severe and warrant a call to a plumber immediately.

Leaks are a sign that the rod has been disintegrated and needs to be serviced immediately. If the issue is allowed to continue, you run the very significant risk of your water heater tank rusting out and leaking.

Instead of needing to buy a $50 part, you will find yourself shopping for a whole new water heater, in addition to any water damage repairs to your flooring or walls. 

How Much Does It Cost To Replace A Water Heater Anode Rod?

Replacing the anode rod yourself is possible. If you choose to do the work yourself, ensure you are informed of the risks involved and have all the necessary tools. It will cost you more in the end if you or someone helping you gets injured or if more extensive damage is done to the water heater. 

Replacing the anode rod itself can cost around $50. Most local home improvement stores carry anode rods. Hiring a professional to do the work could cost about $300, depending on the area you live in, whether it is an emergency call or it is a weekend or holiday. Some plumbers will charge a service call fee as well. 

Before starting any work, check the warranty for your water heater. If you are not the original owner, you can go to the manufacturers’ website and enter your water heaters information to see if any coverage is still available to you.  

Final Thoughts

In most cases, lack of maintenance is the reason for needing to replace an entire water heater. Along with checking for new sounds or smells coming from the water heater, be sure to check the anode rod. This one crucial step will save you thousands of dollars, and stress, in the long run. 



Hubert Miles | Licensed Home Inspector, CMI, CPI

Hubert Miles is a licensed home inspector (RBI# 2556) with more than two decades of experience in inspection and construction. Since 2008, he has been serving South Carolina through his company, Patriot Home Inspections LLC. As a Certified Master Inspector, Hubert is dedicated to providing his expertise in home inspections, repairs, maintenance, and DIY projects.