Room controller with clock function (day timer) for wall mounting. Suitable for controlling central heating, hot water underfloor heating, night storage, warm air heating, etc. Extremely simple operation thanks to separate setting of the day and night temperatures. Additional switch for 3 programs under the housing cover, day/automatic/night. Selectable switching behavior, pulse width modulation or 2-point control method. Adjustable cycle duration of 10 or 25 minutes (sum of on and off times of the pulse width modulation). Clock power reserve in the event of a power failure is approx. 100 hours. Range restriction in the setting button to reduce heating costs. Timer output for controlling additional controllers with temperature reduction. 2 control lamps, heating on and setback mode.