Abstract: A vortex recirculating combustion head for a burner, including: a housing having a through-bore, an upstream end, and a downstream end, the upstream and downstream ends arranged at opposite sides of the through-bore, the housing configured to receive combustion air; a primary fuel inlet arranged adjacent to the upstream end of the housing configured to introduce a primary fuel stream into the housing; a secondary fuel inlet arranged downstream of the primary fuel inlet configured to introduce a secondary fuel stream into the housing; a flame retention head including a diffuser plate secured to the downstream end of the housing, the diffuser plate including a plurality of openings, a plurality of fins, and a ring; and, an extension member secured to an exterior surface of the flame retention head.