Do you get annoyed at the amount of water you waste, when you turn on the hot water tap and wait for what seems ages for the hot water to come out? This product the
Rinnai Smartstart could be the answer to saving water in your household.
This is how they say it works:
Allows you to pre-heat the water in the pipes before you turn on the hot tap
Simply activated by the 'preheat' button on any Water Controller
Takes a minute or two to warm up depending on the size of your home
Saves literally tens of thousands of litres of water over the life of your hot water system
Plumbing is designed as a 'ring-main' or loop around the house. In existing homes, a return line can be plumbed in from the furthest point back to the INFINITY
Even though you have to press the button in advance I think this could work. You know you are going to have a shower - before you get undressed you press the button - then when you are ready for the shower you have instant hot water

.
Combine this with the water timer and your water bills could plummet

.