Do not get a Geyserwise

Some years ago, we purchased a solar water heater from a CTCC tenderpreneur in order to get the slight discount. In return for money, we received a solar heater, leaking pipes, pipes which still rattle, a leaking roof, and a Geyserwise. The Geyserwise is technology seemingly based on those digital wrist watches from 1975 or an alarm clock from 1980. One has to decide when hot water is required months or weeks in advance and don't dare change your mind. So we have had many cold showers, and honestly, an on/off switch would be a huge improvement.