Abstract: The valve includes an intake duct (13) for conveying water into the valve, an externally projecting tubular body (20) of a transparent with an internal cavity (21) and a flow indicator rod (40), slidable inside the valve, with a lower portion in the intake duct (13) and an upper indicator portion in the internal cavity (21) of the transparent body (20). The upper, indicator portion has a first upper area (46) able to indicate no water is flowing and a second, lower area (47) able to indicate that water is flowing through the intake duct (13).

Abstract: The manifold includes a sleeve element (10) extending longitudinally about an axis (x), formed in one piece of plastics material and having a plurality of pairs of apertures (11, 12) distributed along the manifold. The apertures of each pair are aligned transversely with each other for engaging and locking on the manifold respective pairs of tubular metal elements (20, 30) connectable mechanically the one to the other (16) and to a branch (T) of the heating system.