7 Signs Your Water Heater A-Needs a New Anode Rod

There's nothing worse than having dirty or smelly water coming out of the hot water tank. In most instances there's no reason to panic; the explanation is most likely that you require a water heater anode rod replacement. The anode rod plays an important role in protecting the water tank from corrosion. It gradually wears out, and every few years, you need an anode replacement.

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What Is an Anode Rod, and What Does It Do?

An anode rod is a long metallic probe inserted in the top of an electric or gas-fired hot water tank. The probe is made of a material that corrodes faster than the steel that forms the exterior of your water tank. It's known as a sacrificial anode because it's deliberately made to corrode faster.

The reason you have an anode rod is that water is corrosive to steel. Although most hot water tanks have a ceramic glass lining, there are still steel components in contact with the water. Without the anode rod, these exposed parts will corrode and cause a leak.

What Are Anode Rods Made From?

Although strong, steel is vulnerable to corrosion. The iron in steel reacts with oxygen ions in the water to create iron oxide or rust. Tank corrosion can be prevented if there's another material that corrodes faster, such as the anode. These materials are higher on the electrochemical series and sacrificially corrode instead of steel. Common anode materials include:

Magnesium Anode Rods

Magnesium is an excellent sacrificial material because of its larger electrochemical potential compared to steel (iron). It's the best anode for soft water. Magnesium anodes may wear out more quickly and need frequent replacement.

Aluminum Anode Rods

Aluminum anodes are good for hard water, which tends to be slightly alkaline. They last longer than magnesium but aren't as effective in preventing corrosion.

Aluminum Zinc Anode Rods

These rods have a small amount of zinc that helps reduce the smell of sulfur or rotten eggs from the harmless bacteria found in some water supplies.

How Long Does an Anode Rod Last?

Anode rods usually last between three and five years. The actual lifetime depends on many factors, including the water quality and hot water use. The best way to decide the correct replacement frequency is to check the anode rod every year until you know how long it lasts. Your water heater manual will show how to replace the anode rod in the water heater. Alternatively, ask a water heater installer to check it.

What Are Some Signs That My Anode Rod Needs to Be Replaced?

Apart from regular inspections, take note of these warning signs that indicate you need a water heater anode rod replacement. These include:

• Discolored water: If the hot water is reddish brown or discolored, it shows that the anode rod has reached the end of its life and the center steel core is corroding. To prevent tank corrosion, get your water heater inspected as soon as possible.

• Water smells rusty: Although the water may not be discolored, a rusty smell is another sign corrosion is taking place and the anode rod is depleted.

• Rotten egg smell: As the anode rod corrodes, the active material converts into a sulfate, particularly if your water is high in sulfur. The smell of rotten eggs coming from a hot water faucet shows the presence of sulfates and that the anode rod is worn out.

• Popping and banging noises: These noises are caused by sediment that collects around the heating elements and at the bottom of the tank. The pops are caused by the noise trapped water bubbles make as they escape from under the sediment.

• Faucet aerators get clogged. If the small aerator filter in the kitchen faucet gets blocked, it's likely to be caused by fine rust particles or sediment coming from the hot water tank, showing that the anode needs changing.

• The water heater is more than five years old. If you've never changed the anode and the water heater is more than five years old, it's likely the anode rod is corroded and should be replaced.

• Water leaks. Water collecting in the drip tank indicates you may have a leak and that the anode rod is exhausted.

What Happens If You Ignore Water Heater Anode Rod Replacement?

The reason a water heater tank has an anode rod is to prevent corrosion of the outer skin of the tank. If the anode is gone, the water tank may corrode until it leaks. When that happens, the tank can't be repaired.