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A Guide to Water Heater Sacrificial Anode Rods

Water is known for causing rust, corrosion, and harm to metals. So have you ever wondered what prevents water from damaging the metal of your water heater tank? This protection is often provided by a sacrificial anode rod installed in your unit. Find the answers to all of your sacrificial anode rod questions here, brought to you by the plumbing experts at Bonney.

What Is a Sacrificial Anode Rod?

What exactly is a sacrificial anode rod? As the name suggests, a sacrificial anode rod is a long metal rod that hangs down from the top of the water heater. It “sacrifices” itself to protect the metal of your water heater tank.  

As we explained in a recent post about the Folsom Pinhole Water Leaks, when two dissimilar metals are connected within a plumbing system, one metal will experience galvanic corrosion while the other experiences galvanic protection. The anodic (less noble) metal will corrode to protect the cathodic (more noble) metal. 

Water heater manufacturers use this plumbing insight to their advantage by adding a large anodic metal rod into your unit. This sacrificial anode rod experiences galvanic corrosion while offering galvanic protection to the metal of your water heater tank.

In more simple terms, this metal insert attracts all of the corrosion and mineral buildup that your water heater has to offer. As the water eats away at your sacrificial anode rod, it leaves the metal of your water heater tank untouched. 

Once the sacrificial anode rod becomes corroded or encompassed in mineral buildup, it can no longer protect your unit. At this point, the water and minerals in your water heater will begin eating away at the tank itself.

How Often Should I Change the Sacrificial Anode Rod?

So how often do sacrificial anode rods need to be replaced? After 2-4 years, the sacrificial anode rod will become unable to offer full galvanic protection for your water heater tank. At this point, the water will begin eating away at the tank itself. This is why it is essential that you have your sacrificial anode rod changed every 2-4 years. 

What causes some sacrificial rods to corrode faster than others? Water quality is the primary source of this difference. Hard water will lead to enhanced mineral buildup. On the other hand, water softened by the use of a sodium water softener will corrode your anode rod even faster due to the trace amounts of sodium in the water. If you have a softener you might consider replacing the anode rod every 2-3 years to prevent premature tank failure.

What Happens if You Don’t Replace Your Sacrificial Anode Rod?

What happens when you don’t replace your sacrificial anode rod? Unfortunately, skipping out on this routine service can have some costly and inconvenient side effects:

  • Diminished Water Heater Lifespan: Without a sacrificial anode rod replacement, the average tank water heater will last a maximum of 8-12 years. However, your water heater may start failing as early as 5 years old without this essential care. Regular sacrificial anode rod replacements could help your water heater last up to 20+ years.
  • Voided Warranties: If your water heater is protected by a warranty, your manufacturer will pick up the tab on eligible repair and replacement services. However, failing to have your sacrificial anode rod replaced may result in a void warranty. Warranty agreements are often contingent upon your unit receiving all of the manufacturer-recommended care—including sacrificial anode rod replacement. You can reference your warranty agreement and your manufacturer care requirements for full details.
  • Seasonal Troubles: A water heater without the routine maintenance it needs will be more susceptible to seasonal issues—such as winter water heater troubles. 
  • Water Leaks and Tank Damage: As your water heater tank begins corroding, you might experience water leaks. Once the tank is compromised, there is no fixing it—replacement is the only option. This could leave you facing the cost of water heater replacement and water damage all at once. 

Can I Have My Sacrificial Anode Rod Checked or Inspected?

Can sacrificial anode rods be inspected? Yes and no… Mineral builds up on the anode rod and creates a large mass of mineral which could prevent plumbers from inspecting your sacrificial anode rod. If they can get it out, this process often results in the crusty mineral mass breaking off with large pieces of the decomposed rod that settles in the bottom of the water heater. Due to the anode rod breaking up when removed, most experts would recommend replacing the rod since it’s already out.

Here is an interesting fact…sometimes an anode rod does not “take”. It is rare, but it can be pulled years later to find it looks fairly new—it never corroded or acted as a sacrifice. This could be the reason for premature (4-6 years) tank failure. If your plumber pulls your sacrificial anode rod out after 2-3 years of service and it looks new, REPLACE IT! You might think that a new-looking anode rod means you are off the hook for replacements, but this is actually a sign that the water is most likely eating your tank.

Water Heater Service in Sacramento

When you are due for water heater service in the greater Sacramento area, Bonney is here for you. Our trusted plumbers can replace your sacrificial anode rod—among other routine services like water heater flushing and regular inspections. We proudly serve homes and businesses in and around Sacramento, including Roseville, Rancho Cordova, Fair Oaks, Citrus Heights, Folsom, Rosemont, and beyond. You can make your appointment here online, or give our local plumbers a call to get started today!