There are two common reasons that the valve will not fully close and dispense water.
1) The valve is installed backwards. Please ensure water is feeding into the female end of the valve.
2) The user's household pressure is <10psi. The valve needs at least 10 psi, preferably 25 psi to fully close the internal solenoid after a watering event. If you suspect this is the case, please ensure your spigot is opened to maximum.