pipe size

handifoot

Hello, I'm going to start replacing some of my old galvanized plumbing with wersbo brand pex. So, can I do 1/2 inch into the water heater and 3/4 inch out?
I plan on running 3/4 as the main line down the center of the house with 1/2 risers to the fixtures.
It just would be easier to do the 1/2 into the water heater as I already have a new 1/2 in line running to an outside hose bib right over the unit.

Ron6519

3/4" into the water heater and 3/4" out of the water heater as the main. Branches off to the individual fixtures would be 1/2"
Ron