The default ideal temperature for is 22°C.
Cosy mode is the mode to choose for when you want the heating on, and you're home nice and warm so you can relax. Two examples of this would be:
You can schedule periods of Cosy from the Cosy app so they start automatically, or you can start them immediately from the control screen (on your way back from building the snowmen).
You can put your system into Cosy mode from the 'now control' screen of the Cosy App, or by pressing the Cosy button on the display.
You can schedule Cosy to turn on automatically, or select it from the control screen at any time.
Press the Cosy button on the display once to view the temperature for Cosy, then press it again to confirm Cosy mode. Cosy mode will last 1 hour when selecting it from the Cosy Display.