Abstract: A burner includes a diffuser in which first openings and second openings are provided for the passage of a mixture of fuel and air delivered to the burner. A distributing element is arranged inside the burner near the diffuser and is provided with further first openings and further second openings for the passage of the mixture. An ionization sensor is arranged near a zone of the surface of the diffuser in a direction substantially parallel to the surface of the diffuser. The first openings are shaped as holes and the second openings are shaped as slits. Two rows of slits are provided in the zone. The rows are separated by a surface portion of the diffuser devoid of openings. The ionization sensor is arranged above the surface portion of the diffuser between the two rows of slits.

Abstract: A burner (1), fed with a mixture of fuel and air, comprising a body (2) consisting of two half-shells having a plane of symmetry, inside said body a Venturi tube (3) being defined, provided with and inlet (4) into which said mixture of fuel and air is introduced, said Venturi tube (3) communicating upwardly with a distributing chamber (5) of said mixture of fuel and air, said distributing chamber (5) communicating upwardly with a burner head (8), closed upwardly by a diffuser (9), on which openings are made for the outflow and the subsequent combustion of said mixture of fuel and air, said distributing chamber (5) exhibits a first portion (6) and a second portion (7), said first portion (6), communicating with said Venturi tube, comprising at least a first stretch (6a; 6c; 6e) having a cross section of substantially constant width and at least a second stretch (6b; 6d) having cross section that increases progressively along a direction parallel to said plane of symmetry towards an end of said distributing cha