Abstract: A heat distributing unit comprising a pair of inner and outer concentric pipes with a valve connected at one end. The valve has separate inlet and outlet lateral flow ports so that circulation from the inlet port goes through the annular space between the inner and outer pipes to the opposite ends thereof and, with the outer pipe being closed and the inner pipe being open at that end, there is reverse circulation back through the inner pipe to the outlet port of the valve. A thermal responsive valve controls the amount of circulation in response to heat and closes off circulation when a predetermined temperature is reached.

Abstract: A hot water heating system is disclosed in which the convectors or radiators are provided with thermostatic valves capable of shutting off the supply water to all radiators. In order to prevent damage to the pump some circulation is permitted at all times by means of a bypass opening in a manifold which directs water to and from the radiators.