This European Standard applies to heating boilers (e.g. with forced-draught burners (unit)) and burners equipped with a fan including all components specified by the manufacturer to be required for the designed boiler operation.This European Standard also applies to heating boilers sold without burners.This European Standard covers the required definitions, the system boundaries, the measurements for the determination of the electrical power consumption and, where applicable, the water side resistance in order to establish the electric auxiliary energy for:Oil-fired forced-draught burners in accordance with EN 267;Automatic forced-draught burners for gaseous fuels in accordance with EN 676;Flued oil stoves with vaporizing burners in accordance with EN 1;Heating boilers sold without burners for:Oil-fired forced-draught burners in accordance with EN 303-1 [6], EN 303-2 [7] and EN 304; Condensing boilers for liquid fuels in accordance with EN 15034;Room sealed boilers for fuel oil in accordance with EN 15035;Heating boilers - Heating boilers with forced-draught burners - Nominal heat output not exceeding 10 MW and maximum operating temperature of 110 °C in accordance with EN 14394;Pellet burners for small heating boilers in accordance with EN 15270.NOTEAll measurements for boilers are carried out in the heating mode only. For hot water production this mode is also relevant.