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Anode Rods Save Water Heaters

How anode rods extend your water heaters lifespanThe average storage tank water heater lasts 12-15 years. Like all averages, some last much shorter and others much longer. If there’s one single thing you can do to assure the longevity of your water heater, it’s to have the anode rod(s) inspected periodically and replaced when necessary.

Anode rods are made of magnesium, aluminum or a combination of aluminum, zinc and tin. These rods are wrapped around a steel core and screwed upside down inside the top of a water heater tank. Smaller water heaters have a single anode rod, while bigger models typically have two or more. Commercial water heaters may have as many as five.

The main function of anode rods is to prevent corrosion of your water heater tank and internal components. Once a water heater tank rusts through, there is no possibility of repair, only replacement. Anode rods prevent corrosion by electrochemical reaction with impurities in your water, which causes the anode rods to waste away gradually. They sacrifice themselves so your tank may live.
Anode rods typically last around five years, but that can vary depending on water quality, usage, temperature and the quality of metal parts. Household water softeners may also speed up the process. Anodes can corrode in as little as six months if the water is over-softened. When there’s no sacrificial metal left on the rod, the tank will quickly rust out. If your faucet aerators start clogging up more frequently, that may be a sign of a deteriorated anode rod. You may notice a slimy gel-like substance when cleaning a faucet aerator.

Another signal could be a “rotten egg” odor emanating from your hot water. The odor is caused by anode rods reacting with otherwise harmless bacteria that feed off of hydrogen gas produced by magnesium anode rods. One way of solving the problem is to switch to aluminum/zinc/tin rods. Some plumbers recommend getting rid of the anode rod(s) entirely but at the price of drastically reducing your water heater’s life span. It’s much less expensive to replace anode rods than the entire water heater.

The only sure way to tell if an anode rod is near the end of its useful life is to remove the tank top and make a visual inspection. Most people don’t know how or don’t want to do this. It’s one of the most important services provided by our technicians for our plumbing service agreement customers. Give us a call if you would like your anode rod(s) checked and don't have a service agreement.