This International Standard specifies the terminology, test procedures and general requirements for the construction and operation of automatic forced draught gas burners, and the provision of related control and safety devices. It is applicable to the following: automatic gas burners (hereinafter called “burners??) fitted with a combustion air fan that are equipped as described in Clause4, intended for use in appliances of different types and operated with fuel gases; total pre-mixed burners and nozzle mixed burners; single burners with a single combustion chamber, for which, where such burners are fitted to a single appliance, the requirements of the relevant appliance standard also apply; single-fuel and dual-fuel burners when operating only on gas; the gas function of dual-fuel burners designed to operate simultaneously on gaseous and liquid fuels, which, for the latter, the requirements of ISO22968 also apply. It is not applicable to burners used in direct fired processes either with defined combustion chamber applications or where the combustion chamber wall surface temperature is greater than 750°C or the heat-transfer medium temperature is greater than 500°C.