The invention is directed to a heating assembly comprising, in combination, a main radiator (1) for fluid flow and an electric radiator. The latter is disposed on one face of the main radiator (1) defining its general plane, and consists of a plurality of independent heating elements (6). Each of these heating elements (6) comprises an elementary electrical heating body (7), having connecting means (31, 31′) for connection to an electrical power source, and a finned element (8). These heating elements (6) are assembled on a connecting structure of the electric radiator on the face of the main radiator (1).