A solid fuel boiler burner has a rotary combustion chamber mounted in casing. The casing is connected by hooks to a gearwheel. The gearwheel is mounted rotationally between a pair of cage bearings. The gearwheel and a compensating and pressure plate have openings for a inflow of air from a blower chamber through an adjustable screen. The adjustable screen controls a ratio of primary to secondary air. A worm feeder delivers fuel to the combustion chamber through an outlet thereof. The worm feeder has an axially placed aeration duct therein.