Abstract: A radiator for heating installations comprises an external container consisting of component elements, and a heat exchanger which goes through the entire assembly of elements forming the radiator acting as the tie-beam which holds the elements together. A second tie beam is positioned in the upper part of the elements to hold them together. The finned tube which constitutes the heat exchanger, is provided with an internal coaxial tube, of length slightly smaller than the external tube. The primary heating fluid returns through the internal tube so that the supply of the fluid is carried out from a single extremity of the apparatus. Since the walls of the radiator are not subjected to high pressure, the radiator may be manufactured of material of modest mechanical resistance, for instance plastic material.