Why does "cast iron" matter?

Using cast iron to contain, heat, and circulate the water inside a boiler provides unbeatable ruggedness. What Ray has done is bring ultra-modern efficiency and performance to cast iron's universally recognized longevity. While boilers that use steel or aluminum can provide similar efficiency, they frequently require additional measures in piping, water purity monitoring, and ongoing maintenance to keep up to peak efficiency. Plus, the thermal retention of a cast iron boiler is inarguable -- just think of that old cast iron skillet grandma fried eggs in! By holding heat longer, Ray provides steady heat with the least possible fuel usage.