Hi Brenden,
That is one extremely broad question.ie:
A: Is it a 3.6KW HWS or a 4.8KW HWS
B: How long do you both spend in the shower.
C: Do you take hot baths
D. Do you have Water saving shower heads.
E: HWS thermal efficiency
F: How many times do you wash the dishes.
G: How many litres of hot water do you use per day etc etc etc
This you will need to work out for yourself.
Regards
John
