Manufactured by Buderus, the world leader in cast iron boiler design and production. The G234X construction consists of flexible GL-180M cast iron, designed to resist thermal shock for long life and a high silicone cast iron surface for excellent corrosion resistance. It has staggered contoured fins for optimum heat transfer and efficient operation, precision push nipples sectional construction and deluxe, heavy gauge blue enameled jacket for a clean finished appearance. There is a full 3" of thermal insulation for minimal standby heat losses coupled with an integral draft diverter for low profile. All models are easily converted to propane. The G234X offers low emissions with Premixed Burner Technology. Durable, quiet and efficient, Buderus boilers are designed for many years of trouble-free operation.