You have a heater in the living/sleeping area and a radiator in the bathroom. The heater in your living/bedroom is electric. You operate it with a button on the device itself. In your bathroom, you have a radiator. A thermostat hangs under this. You set the temperature on that.

Are you going away for a longer period of time?
Then set the heating to 15 ºC. That way you won't burden the environment unnecessarily.