So I've been looking at layouts and pretty much set now on having a 300 litre UVC as the main DHW supply for the house.  This will be heated to 50 ish by the ASHP with an overnight kick once a week with the immersion to 65 for the legionnaires cycle. It will also be the dump for the solar PV - I expect in summer given the tank immersion will be at 65 ish then the hot will be very hot ! Question is - TMV, where and how many ..? Ensuite has the bath and shower, bathroom only ha