Article 3
1. The following shall be excluded from this Directive: - hot-water boilers capable of being fired by different fuels including solid fuels, - equipment for the instantaneous preparation of hot water, - boilers designed to be fired by fuels the properties of which differ appreciably from the properties of the liquid and gaseous fuels commonly marketed (industrial waste gas, biogas, etc), - cookers and appliances designed mainly to heat the premises in which they are installed and, as a subsidiary function, to supply hot water for central heating and sanitary hot water, - appliances with rated outputs of less than 6 kW using gravity circulation and designed solely for the production of stored sanitary hot water, - boilers manufactured on a one-off basis. 2. In the case of boilers with a dual function, that of heating premises and also providing sanitary hot water, the efficiency requirements referred to in Article 5 (1) concern the heating function only.