What if water heaters could become more energy-efficient, and produce less carbon when being manufactured, by use of metal 3D printing technology? This concept makes use of the unique possibilities of metal 3D printing to create advanced geometries in copper or aluminum to better transfer heat from heating elements to water. With a clever self-isolating design the product will be smaller than current products, and need less parts for assembly. This evolution of water heating technology will make products more sustainable to produce and more energy-efficient to use.