Plumb in series to save energy. The first tank in series only ever
turns on if the second tank falls below a certain *critical*
temperature. It then delivers warm water to the second tank instead of
cold water, so the second tank has the capability to heat it hotter.
This way you normally only have heat loss from the second tank.
Without two tanks of water already heated and available on demand,
he will not have as much hot water available. And you still have to
the second tank warming up water to some temp, so I don't see the
energy savings. If energy savings is the goal along with continuous
amounts of hot water, then I'd just go with a tankless, assuming the
install is reasonable.
HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.