I have a 2 1/2 story house in southeast SC. It is about 4400SF and was built in 2006. The home is all electric. I have two 80 gallon electric water heaters - both located in closets on the third floor. They don't leak, but given their age, I am thinking of replacing them. I was wondering if I really need 80 gallon heaters, and if not, what would be recommended. I assume that one services the second and third floors and the other the first. There are two showers on the second and one shower on the third floor. The first floor has one shower (no tub), washing machine, dishwasher and kitchen sink. What would you advise and why?