Abstract: In its simplest sense, the burner of the present invention includes a swirl chamber for creating a swirling flow path for primary combustion air. The burner also includes means communicating with the swirl chamber for introducing low heating value gas to the primary combustion air for discharge with the air into a flame zone. Also provided are means adjacent to each other for introducing secondary air and for introducing secondary low heating value gas positioned so that the secondary air and secondary low heating value gas intersect the flame zone, preferably above the region of the recirculating core of the flame and at such a point that the secondary air and low heating value gas have a minimal effect on the swirl aerodynamics of the flame.