The SRT321 is a battery operated wall thermostat. Using a big wheel on the device the user can preset the desired target temperature in the room. By verifying the target temperature with the measured real temperature closed to the device the unit decides how to operate a wirelessly attached power switch that is attached to the heater. In parallel a central gateway of Z-Wave control software can set the target temperature using Z-Wave. This enables to realize a time scheduled zone heating. The thermostat itself does not have any internal timers but executes the wireless settings and the local setup.