A pre-mix burner assembly comprising: a jet pump comprising a combustion air tube, a flue gas inlet, and a suction chamber; the combustion air tube receiving combustion air and having an inlet at one end and a combustion air nozzle at the opposite end, the combustion air nozzle tapering to an outlet having a smaller diameter than a diameter of the combustion air tube, the combustion air tube connected to a combustion air fan; the flue gas inlet connected to the suction chamber and a source of flue gas; the suction chamber surrounding the combustion air tube and the combustion air nozzle, the suction chamber having a jet pump nozzle with a jet pump discharge; a fuel gas inlet connected to the combustion air tube, wherein the fuel gas inlet comprises a manifold surrounding the combustion air tube and wherein there is at least one fuel gas inlet through a wall of the combustion air tube connecting the manifold to the inside of the combustion air tube to allow fuel gas to mix with the combustion air in the combustion air tube to form a combustion air and fuel gas mixture, wherein the combustion air and fuel gas mixture exiting the combustion air nozzle creates a negative pressure in the suction chamber and draws flue gas from the flue gas inlet into the suction chamber, the suction chamber receiving the flue gas; a burner housing positioned downstream of the jet pump discharge to receive a mixture of combustion air, fuel gas, and flue gas; and a burner block connected to an outlet of the burner housing. a jet pump comprising a combustion air tube, a flue gas inlet, and a suction chamber; the combustion air tube receiving combustion air and having an inlet at one end and a combustion air nozzle at the opposite end, the combustion air nozzle tapering to an outlet having a smaller diameter than a diameter of the combustion air tube, the combustion air tube connected to a combustion air fan; the flue gas inlet connected to the suction chamber and a source of flue gas; the suction chamber surrounding the combustion air tube and the combustion air nozzle, the suction chamber having a jet pump nozzle with a jet pump discharge; the combustion air tube receiving combustion air and having an inlet at one end and a combustion air nozzle at the opposite end, the combustion air nozzle tapering to an outlet having a smaller diameter than a diameter of the combustion air tube, the combustion air tube connected to a combustion air fan; the flue gas inlet connected to the suction chamber and a source of flue gas; the suction chamber surrounding the combustion air tube and the combustion air nozzle, the suction chamber having a jet pump nozzle with a jet pump discharge; a fuel gas inlet connected to the combustion air tube, wherein the fuel gas inlet comprises a manifold surrounding the combustion air tube and wherein there is at least one fuel gas inlet through a wall of the combustion air tube connecting the manifold to the inside of the combustion air tube to allow fuel gas to mix with the combustion air in the combustion air tube to form a combustion air and fuel gas mixture, wherein the combustion air and fuel gas mixture exiting the combustion air nozzle creates a negative pressure in the suction chamber and draws flue gas from the flue gas inlet into the suction chamber, the suction chamber receiving the flue gas; a burner housing positioned downstream of the jet pump discharge to receive a mixture of combustion air, fuel gas, and flue gas; and a burner block connected to an outlet of the burner housing.