HL-2/3 series two-way/ three-way motorized valves are used to control the cool/heat water flow through the fan coil units. When a thermostat sends the controlling signal to the motorized valve, the valve is opened with water flowing from B to A (Fig. 1), and when the signal disappears, the valve, with the help of its own spring, returns back to its original place to close the valve so as to stop the water flow(Fig. 2).