Abstract: A heating system that allows independent control of the temperatures within different rooms in a building by independently controlling the flow of heating fluid to each room in response to a thermostat provided in each individual room. The output of the thermostat controls the operation of a three-way valve upstream of a radiator or convector in each room. When the room temperature is at or above the setpoint for that room, the valve operates to divert all heating fluid flow through a bypass pipe or shunt extending from the valve to the outlet of the radiator or convector. When the temperature drops below the setpoint, the valve operates to resume heating fluid flow through the radiator or convector while shutting off heating fluid flow through the bypass pipe. In another embodiment, independent control of room temperature in heated air distribution systems, is effected by thermostatically controlled louvers provided at the heated air register in each room.