Valve unit for a heating circuit, comprising: - a valve body housing plug means (3, 4, 5) for varying the flow of a thermal fluid, - said plug means (3, 4, 5) being movable along an operating direction and being configured for being driven by thermostatic control means or by thermoelectric head means; - a first connection portion and a second connection portion connected to said valve body respectively for connection to a first outlet and a second outlet of said hydraulic circuit to enable said thermal fluid to enter and exit said valve body, - a third connection portion suitable for enabling connection to, and the passage of said thermal fluid along, a heating body of said heating circuit; - said first connection portion extending along a first axis lying on a plane also containing said operating direction; further comprising movable coupling means (14, 16) by means of which said second connection portion is connected to said valve body, said movable coupling means (14, 16) being configured to enable the relative position of said second connection portion to be varied with respect to said first connection portion to adapt to different installation configurations in which said first outlet and said second outlet have any reciprocal distance and reciprocal orientation, wherein said movable coupling means (14, 16) comprises a first coupling portion connected to said valve body in a stationary position, and a second coupling portion obtained on said second connection portion and configured for coupling in a movable manner with said first coupling portion, wherein said movable coupling means (14, 16) comprises sealing means interposed between said first coupling portion and said second coupling portion and retaining means arranged for preventing separating of said second coupling portion from said first coupling portion, wherein said first coupling portion comprises a receiving portion defining a chamber and connected in a stationary position to said valve body, and said second coupling portion comprises an inserting portion obtained on said second connection portion and configured for being slidably and rotatably received in said chamber of said receiving portion, and wherein on the receiving portion, in an internal surface, a relief zone is provided that is shaped for restingly receiving the retaining means when the inserting portion is in configuration of maximum projection from the receiving portion. - a valve body housing plug means (3, 4, 5) for varying the flow of a thermal fluid, - said plug means (3, 4, 5) being movable along an operating direction and being configured for being driven by thermostatic control means or by thermoelectric head means; - a first connection portion and a second connection portion connected to said valve body respectively for connection to a first outlet and a second outlet of said hydraulic circuit to enable said thermal fluid to enter and exit said valve body, - a third connection portion suitable for enabling connection to, and the passage of said thermal fluid along, a heating body of said heating circuit; - said first connection portion extending along a first axis lying on a plane also containing said operating direction;