StellaZ is a wireless Z-Wave controlled actuator suitable for heating, ventilation and air conditioning systems. Sensor, controller and actuator are combined in a single device to allow a self-sufficient energy-efficient room control. The device has four different modes (Normal, Energy saving, Frost protection, direct valve control via Z-Wave) to control and regulate the temperature. It is also possible to readout the temperature via wireless Z-Wave requests. Open windows are automatically detected and lead to a temporary reduction of the heating power to save energy.