Abstract: This bio-fuel furnace includes a combustion unit and separate fuel feed unit mounted atop the combustion unit. The combustion unit includes a cylindrical burn pot, a preheat module, an expansion bowl and a primary heat exchanger supported by an inner frame and enclosed by an outer casing. The preheat module is a rectangular box having an internal spiral baffle. The burn pot is seated within a central opening in the preheat module. The expansion bowl is seated atop the preheat module and the primary heat exchanger is mounted above the expansion bowl. An inlet fan blows inlet air through the preheat module and into the burn pot and an outlet fan draws exhaust air around the primary heat exchanger from the combustion unit. The fuel feed unit has an internal storage bin and a rotating scoop arm deposits the bio fuel into the combustion unit.