An ENERGY STAR® certified storage tank water heater with condensing technology operates much like a conventional gas hot water tank but with technology enhancements designed to increase energy efficiency and durability.

A condensing storage tank water heater offers a ready reservoir of hot water just like a conventional gas water heater but is much more efficient because of how heat is transferred from the energy source to the water. A condensing heat exchanger has more surface area than a conventional non-condensing heat exchanger, enabling water condensation from flue gases. This process captures more heat, greatly improving efficiency. They also have more efficient burners, heat exchangers and better insulation.

A cross-section diagram of a condensing storage tank water heater, with labels for: sealed combustion intake & venting, hot water to tap(s), cold water in, storage tank, high-efficiency heat exchanger transfers heat into water, relief valve discharge line, condensate to drain from combustion process, sealed combustion burners for efficiency.

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