Set 1 timer ON to 10am in the morning to commence heating, in most states for a large part of the year modern solar panel systems will be generating enough electricity to provide power to the iStore and heat your water for free. Depending on the number of people in your household the OFF time to 16:01 where the volume of water is sufficient for all shower requirements in 24 hrs. If the nighttime usage is large enough to use all the water and not leave any more for the people showering in the morning then set the OFF1 time to 20:01/21:01/22:01 for a reheat to take place in the evening after usage. NOTE if you have peak evening tariffs then it may be more suitable to set a second timer to commence after your peak period such as ON2 23:00 to OFF2 03:01.