CALDAIA, UTILIZZANTE ENERGIA ELETTRICA, ATTA A FORNIRE ACQUA CALDA PERRISCALDAMENTO E PER USO SANITARIO

The boiler substantially comprises two or more containers, of which at least one is intended for domestic water and one is intended for water for heating, each of which containers are provided with an electrically powered heat source such as a resistance, and which are in a mutual position such that there is heat exchange between them although the waters are kept completely separate at all times according to their use. The containers are placed one above the other and have at least one common surface separating them for heat exchange, and the upper container which is intended for water supply for the heating system is provided with a hermetically sealed expansion vessel which takes up the changes in the volume of the water. In a variant the two containers are contained one within the other and the inner container is composed of three superimposed cylindrical chambers intercommunicating with the heating electric resistance located in the intermediate chamber. The walls separating the two fundamental containers are strong transmitters of heat and have any shape and profile.