The SIR 321 is a wirelessly controllable 3 KW wall switch that integrates a easy to use timer function. With this the user can turn on a boiler or a heater/cooler right on the slot and define a maximum heating/cooling time to prevent that the forgotten device continues to draw power when not needed anymore. Z-Wave allows to set the timer function with a granularity of 1 minute, while the local operations defines times between 30 min and 2 hours. An optional temperature sensor turns the device into a temperature monitoring device. The SIR fits into both UK and European 60 mm wall boxes.