Abstract: A heating stove for burning woodlike organic material having a fire box for receiving material to be burned substantially centrally therein. The walls of the fire box are sealed to render it substantially air-tight. At least one substantially vertically aligned draft tube depends downwardly from the cover of the fire box into the interior thereof for receiving combustion air at substantially atmospheric conditions from the upper end thereof and directing a flow to impinge upon the hearth adjacent the material to be burned from above and substantially in a vertical direction. Flue means are mounted on the fire box above the material to be burned and in spaced relationship with respect to the draft tube for removing the products of combustion and maintaining the fire box at a pressure below atmospheric pressure.