Duo-boiler for pellets, wood, electricity or oil, which give you choice and comfortable heat. Ariterm Biomix 20 has one furnace adapted for pellets/oil combustion and one furnace for wood. Both furnaces have large heat radiation areas. The wood furnace takes 35 cm logs on the ceramic firing grate. When burning wood the boiler works with under-combustion according to the so-called self-draught principle. With pellets/oil combustion the boiler works with over-combustion. Biomix 20 is equipped with a 8 m built-in and exchangable cooling/tap hot water coil. Environmentally approved for use with accumulator tank.