the heater should work off your dual electric time clock settings usually about 12 30 till 7 30 or 1 30 till 8 30 this when you should be supplied with your CHEAP rate electric times may be different with other suppliers. All i can say is leave it switched on and see if you have any hot water the next day the heater thermostat should switch it off when desired temp is reached
wirecutterman, February 2011
