Abstract: A burner system is described for burning granular pellets and similarly sized solid biomass heating fuel, e.g. wood pellets. It includes an air tight fire chamber having an exhaust outlet in an upper region thereof and a burner (10) in the bottom thereof for converting the solid fuel to fuel gases and ash in the presence of a limited air supply and combusting the gases formed. The burner comprises upright co-axial inner (12) and outer (11) cylindrical walls providing a confined central gasification/combustion chamber surrounded by an annular combustion air manifold (15). The annular combustion air manifold (15) is closed at the top and bottom with an air inlet (16) in the outer wall and a plurality of spaced aperatures (17) arranged in upward rows in the inner cylindrical wall providing air inlets from the combustion air manifold to the combustion zone of the chamber. A grate at the bottom of the gasification/combustion chamber holds the solid fuel while allowing ash to pass through the grate.