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Plumbing and heating expert Richard Trethewey takes host Kevin O’Connor for an inside look at a water heater at the end of its life. Richard explains to Kevin how most folks don’t think about their water heaters until it’s too late, so he cuts open the tank to show Kevin what occurs inside.

Top 3 Reasons Why Water Heaters Fail

1. Steel and water don’t mix

The typical water heater in the U.S. is a gas-fired tank model consisting of a steel tank with a glass lining. While the glass serves to separate the water inside the tank from the steel, water will eventually make it through. When it does, the steel begins to oxidize (rust), leading to a breakdown of the materials in the tank. Indicators of this happening are rust around the flue passageway (essentially the tank’s chimney), and around the water outlet fittings.

But, the tank might look absolutely fine on the outside while being a total mess on the inside.

2. The inside is a mess

If someone were to cut open the average water heater once it’s past its serviceable life, they might startle at what they see inside. Rust, sediment, mineral build-up, and other general ugliness that floats around in potable water is gross. They might even notice what looks like a rotten growth hanging down from the underside of the tank. This is the anode, and it’s a sacrificial rod meant to save the tank from rot. Once it’s gone, the tank is next.

3. Corrosion happens

When a water heater is new, the interior of the tank is generally shiny and glazed. However, once the anode is devoured by corrosion, the water will start on the inside of the tank and its components. Also, as minerals in the water build-up, they form barnacle-type chunks of sediment and sink to the bottom of the tank.

Set Reasonable Expectations

Homeowners should set reasonable expectations for their water heater. Ten to 12 years is typically the max the average water heater can go unserviced. If the user changes the anode rod every 3 to 5 years, they may be able to expect 20 years from their water heater.

If a water heater is around those ages, homeowners should consider replacing it before the inevitable leak occurs.