Water heater geyser(15 lit) for bathroom. We use geyser from morning 6am to 11:30 am only. So which would save power keeping the geyser on automatic mode or turning it "ON" in the morning and turning it off at 11:30 am. I know for e.g if the temp is set to 60 deg, on automatic mode whenever the temp fall below 60 say 59 , it would again heat up just 1 deg. Also the geyser are insulated. But if I use manually turning it on & off as above. It will definitely initially have to use power from room temp to the set 60 deg and I think it doesn't take much time. But remain off for rest of the day after 11:30 am.