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How long will your water heater last? Your anode rods will tell us

Description

An anode rod is a rod made of “sacrificial” metal. Like batteries, the anode produces an electrochemical reaction in the tank. The anode wears out slowly rather than the tank lining. As long as the anode is present and functioning, almost all corrosion or oxidation in the tank lining is prevented.

Access

For all consumers who are purchasing a new water heater, an important aspect of the new appliance is the accessibility of its anode rod. At the top of the water heater is a part called the hex head. It is visible or not. If not visible, the hex head is located under the sheet metal top or is connected under the hot water outlet. You shouldn’t have to settle for a hard-to-find anode rod. I recommend not buying this water heater. Look for a water heater with an easy-to-find hex head.

For commercial water heaters, the outer sheet metal top of the water heater must always be removed to access the anode rod. The hex head is rarely found exposed, whether it is an electric or gas heater. As you remove the top of the heater, mark the top of the heater to make it easier to assemble later. At this point, the anode rod hex head can easily be found on any commercial electric heater. On gas heaters, the hex head will probably be easy to find if you have only one vent. If you have more than one vent, it can be more difficult to locate.

Aluminum

An anode is made of aluminum, zinc, or magnesium. It is formed around a wire that runs through the center of the rod. Hard water areas of the country often have aluminum rod water heaters installed because aluminum is the best material for hard water conditions. If your anode rod has deteriorated down to the wire or is completely gone, this is usually a sign of hard water. However, be careful with the aluminum anode rods. Science believes there is a link between aluminum in the diet and Alzheimer’s disease. Do not drink or cook with hot water from a tank that uses an anode rod made of aluminum. To determine if you have an aluminum anode rod, remove it and then bend it. If it bends easily in your hands, it is probably made of aluminum.

Combination anode

Typically, anodes are installed 3/4 in. Hex heads screwed into the top of the tank. However, a combined anode is attached to the nozzle of the hot water outlet pipe, also screwed on top. All water heaters have at least one anode rod. Some water heaters have longer warranties because they have two anode rods. If there are two anode rods, it is because one is attached to a hexagonal head at the top and the other is a combined anode attached to the hot water outlet. Some residential heaters have two anode rods with a hex head and no combination anodes.

To find out if you have a combination anode rod, disconnect the hot water outlet at the top of the heater with a pipe wrench. Don’t forget to turn off the water first! Then feed a stiff wire through the hole where the hot water nipple was. If it stops 3-6 inches straight down, then you have located the combined anode. If the wire doesn’t find anything inside, the anode is somewhere else. The combined anode can be removed with a pipe wrench.

If you do not have a combination anode and want to install one, remove the nozzle from the hot water pipe and replace it with a combination anode rod. The anode nozzle will need to be longer than the thickness of the insulation on top of the heater, which is typically 2 to 6 inches.

Magnesium

Magnesium is used more often than the other metals for anodes. When the water in your area isn’t particularly hard, it’s probably best to use magnesium sticks. However, be careful with magnesium rods when replacing them in an already corroded tank. The electrochemical reaction of the new magnesium anode can cause hydrogen gas to build up in the tank. This can cause water leakage.

Zinc

New water heaters rarely have a zinc rod installed. Zinc rods are actually aluminum rods with a 1/10 portion of the rod being actual zinc. The sole purpose of the zinc in an anode rod is to reduce the smell of sulfur in the water.

Anode consumption

Softening hard water with salt is actually more damaging to the anodes than calcium carbonate, the cause of hard water. Salt can consume an anode up to three times faster than usual. Phosphates can have the same adverse effect on an anode. The anode should be inspected every two years or sooner if you use these water softening agents.

The anode is the reason the heater remains functional for years or even decades. The anodes corrode as expected. Most of the time it corrodes on the top or bottom and exposes the steel wire underneath.

Central cable

The water heater will only be protected if the anode rod has enough metal hanging from it. The steel core wire holds the sacrificial metal at the anode. Be sure to inspect the anode for an exposed center wire every two years at least.

By analyzing an anode rod for exposed core wire, the wire can be coated with calcium carbonate that is easily brushed. This calcium carbonate is not a metal corroded by the anode rod, so don’t worry about removing it.

Anode classification

If the anode rod has more sacrificial metal than the exposed steel rod, then it is still in good shape. However, if the entire surface is covered with calcium carbonate and this calcium carbonate hardens, this will prevent the anode from protecting the tank any longer. This is known as passivation. If the anode has been passivated, it will not only appear that way with the naked eye. To test passivation, you need to bend the anode rod by hand. On the curve, look for small amounts of flaking. The anode should be replaced if there are more areas of the rod with exposed wire than with sacrificial metal. It should also be replaced if the top or bottom of the rod has deteriorated, exposing six or more inches of exposed wire. An anode must also be replaced if the anode is less than half of the 3/4 in. Rod. diameter size. If the anode has been passivated, split over its entire length, or pitted heavily, it might also be time to replace it. When all the sacrificial metal has worn away, the steel rod will begin to wear out. Once the steel rod wears out, the only thing left will be the hex head or the hot water outlet nozzle if it is a combined anode. At this point, the tank will begin to corrode. If the anode is in the condition listed above, tank damage may already have occurred.

Hidden hex head on newer models

Hex heads are threaded sealing plugs approximately 3/4-inch in diameter. They are attached to anode rods on top of the water heaters. Some are easily seen from the top of the water heater. Other times it will be under fiberglass or under a piece of plastic. To locate the hex head, drill a 1/4-inch shallow hole through the plastic top of the water heater. Do not drill deep into the tank. Use a long flat-head screwdriver to probe under the top of the water heater to find the hex head. On gas heaters, the hex head will be the same distance from the flue as the hot and cold lines. In electricity, the anode will be off-center so as not to fall on the heating elements. It may be necessary to dig a few holes to locate the hex head. Once the hex head is found, it should be permanently exposed. Use a hole saw capable of cutting plastic or metal to make a hole large enough to allow future access to the hex head. At this point, use two people to unscrew the hex head: one to stabilize the tank and the other to use a breaker bar and a socket that fits the head. Anywhere from 3/4 inch to 1-1 / 16 inch.

In the future when buying a new water heater, buy only those with hex heads already exposed.

Hidden hex head on older models

To find the hex head on older water heaters, simply unscrew the screws that hold the top in place, mark the location of the top and the water heater with a marker, then remove the top to find the right one. hex head. Unfortunately, many heaters found in today’s buildings have foam tops and cannot be removed. Again, if the hex head is not exposed at the time of purchase, please do not buy that particular tank. Look for a tank with an already exposed hex head.

Anode inspection

Anodes should be inspected at least every two years when using softened water, but at least every four years under normal water conditions. Sometimes the anode location is written in the water heater’s instructions.

Anode installation

To remove the old rod, pull it out as far as possible, bend it, and then pull the rest out. To install the new one, bend the rod directly in the middle, insert it halfway, straighten it against the opening, and install it the rest of the way. Screw in the anode rod at this time. If you can’t screw it into place because it’s too bent, pull it out partially and use the opening to straighten it further. If there is not enough room in the ceiling to install the new anode rod, consider a bonding anode. These anodes have many small links attached to them and look like links on hot dogs. You can also try zinc anodes because they bend much more easily than magnesium anodes. Another way to install an anode is to drain the water heater and angle it just enough to allow easy access to the anode.

Long

The anodes are typically 3 feet 8 inches. The anodes should be only a few inches shorter than the tank itself. Buy anodes that are too long rather than too short. In this way, you can shorten the anode if it is too high.

Printed current rod

Relative to commercial water heaters, there are printed current bars. These rods do not self-generate currents like sacrificial anodes. They get energy from an electrical power source. Many commercial heaters give the location of the printed current bar. They do not need to be replaced during their useful life. They may need periodic cleaning. Just wipe them off with a towel. If rust appears inside a water heater with a printed current dipstick, you should call the manufacturer, call a plumber, or install sacrificial anodes.

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