Premix gas burner and method for manufacturing a premix gas burner

The invention pertains to a premix gas burner, comprising: - a non-cylindrical burner deck unit, comprising a support portion between a circumferential edge and a operational burner deck area, - a cavity in which at least a part of the support portion is arranged, wherein the support portion extends between the first and the second cavity wall portion over a length which is at least half of the expected thermal contraction of the burner deck unit in the support portion plane when cooling the burner deck unit from maximum operational temperature to ambient temperature, and the cavity end wall portion is spaced apart from the support portion edge by a distance that is at least half of the expected thermal expansion of the burner deck unit in the support portion plane when heating the burner deck unit from ambient temperature to maximum operational temperature.