Clean Burn introduces the CB-500-CTB. The large-capacity used-oil coil tube boiler can recycle large volumes of used-oil (3.6 gallons of used-oil per hour)---a larger amount than the company's original CB-200-CTB and CB-350-CTB models. Designed to recycle used-oil and produce hot water, the CB-500-CTB can be used for in-floor, baseboard and space heating, as well as for ice melt applications.