This brand is well known for its long lifespan. Bradford White tanks are the most common in the Kansas City area, with an average lifespan of fifteen years. Most models of Bradford White water heaters are equipped with a magnesium anode rod, which can only be purchased with an AO Smith warranty upgrade. It is also safer than aluminum in water, making it an ideal choice in most situations. In addition to Bradford White, AO Smith produces Whirlpool, ProLine, and Kenmore tanks. The Tempra tankless model from Stiebel Eltron boasts patented Advanced Flow Control technology, which allows for even heating when water flow varies. This feature helps the tankless water heater keep the water at a steady temperature even if there is a sudden rise in demand. Similarly, tankless electric water heaters from other manufacturers do not respond to fluctuations in demand and may cause sudden cold showers.