EKO DUO 150 hybrid boiler, 500K BTUEKO DUO 150 hybrid boiler, 500K BTU Commercial use automatic self cleaning hybrid boiler built for larger hydronic systems, with configurable ash removal and hopper side options on the EKO DUO platform. Key Benefits Automatic self cleaning burner with rotary cast iron design for continuous commercial duty operation Flexible multi fuel capability for coal, pellets, grains, and biomass up to 1 1 2", plus manual feeding for wood chips and peat briquette