D'Alessandro CSI series model 20 biomass boiler with hot water production. CONSTRUCTION FEATURES: “Marina” type boiler with smoke passes for the production of hot water for heating; Steel boiler body; Insulated doors for boiler inspection and cleaning; Cast iron burner with mechanical firebox; Fuel loading hopper; Variable-speed fuel conveyor screw; Primary and secondary combustion air system; Power supply voltage: 230 V.