Heat the water you expect to use
The attraction of a smart cylinder is being able to manage the amount of stored hot water against your routine. A shorter period of demand need not mean heating the whole tank every time. That does not make cylinder size irrelevant: the installation still needs to suit the busiest periods, including occasions when several people want hot water close together. Describe those patterns at the survey, including any changes you expect at home, so the proposed capacity and control approach are considered together.

