Wireless radio clock thermostat, battery-operated, for wall mounting. It transmits to the Instat 868-a receiver and is suitable for controlling central heating, warm water underfloor heating, warm air heating, night storage heating, etc. Can be used as a timer pilot clock in conjunction with Instat 868a4 or -a6. Fully automatic setting of the time as well as summer and winter time. Large, easy-to-read display. Self-learning heating curve, the temperature is reached at the set time. Weekly and separate daily program: pre-set and customizable lifestyle time programs. Unauthorized access protection prevents unauthorized adjustments. Combined holiday and party function for temporary temperature reduction or increase for hours or days. Specification of upper and lower limits for temperature setting and much more.