Abstract: A self-aerating radiant gas burner assembly comprises a mixing chamber (1) closed except for an air inlet (3) into which is directed a gas injector jet (4), of 0.5 to 2.0 mm bore, to induce flow of air through the inlet, the chamber being surmounted by a radiant burner element of ceramic foam material of a porosity between 15 and 40 pores per linear 25 mm and a thickness between 8 and 30 mm, the dimensions within these ranges being selected for a specified gas and pressure range with the relationship that the lower the gas pressure the larger the jet size.