Burner plaque with continuous channels

A burner plaque of ceramic or other high temperature material comprising a plurality of burn ports permitting flow of combustible fluid from a first face of the plaque disposed towards the inside of a mixing chamber and a second face of the plaque on which combustion of the fluid occurs, the burner ports being arranged in rows offset from one another in alternating fashion over a substantial portion of the first and second faces of the plaque, the first and second faces of the plaque defining the thickness of the plaque, the second face of the plaque being provided with a plurality of channels which define discrete lands therebetween, the channels opening out in the second face of the plaque but having a depth that is less than the thickness of the plaque and the arrangement of the channels over the second face of the plaque being chosen to ensure that each of the channels coincides with at least two burner ports in the plaque to reduce the effective length of the at least two burner ports,

• wherein the channels define a plurality of annular or polygonal shapes in the second face of the plaque, each of the channels having a continuous periphery so as to be separate from one another.