A gaseous fuel burner assembly for heating a space particularly an oven of a domestic cooking appliance comprises a gaseous fuel burner separated from the space by a baffle plate, and, also separated from the space by the baffle plate, a fan for withdrawing air from the space via an aperture or apertures in the plate and returning that air to the space via an exit or exits adjacent the edge of the plate, the or each aperture being so located that, during its passage from the aperture or apertures to the exit or exits, the air passes close to the burner. The fan may also draw in air from a plenum chamber behind the oven. The burner may be of the duplex variety and may have two independently controllable burner heads.