hello, you set the timer every 15 minutes minimum, that is to say if you put for example has an electric heater in a bathroom, it will trigger the minimum 15 minutes, and that on the 24 .... time you want, al hour you want is very comfortable, and economical, it sarrêtera al hour you have decided, more forget break if you go away from home. you can "force" the demand of electricity as a normal socket, but your timer is no longer in office, but do not cancel your initial programming provided. a red light indicates that the current passes, it does not heat, do not make noise, I recommend you (ps maximum 3500 watts, not bad).