I've added some text to this image of the back of the water heater. Its not the best graphics in the world but, best I can do.
Its a link because its a bit large for in the forum.
I will drain the water heater and blow out the lines first then do this.
(Hot water heater are is really dirty...dont they clean these after construction?)
(To add antifreeze to my lines)
Put hose in jug.
Turn valve inline with hose
Turn valve C 90 degrees to close it (no pink in tank)
Turn valve A 90 degrees to close it (no pink in water heater)
Fire up pump
Turn on each faucet till hot and cold run pink. Turn off, move to next.
So valve B is some sort of temperature blender? Mine is closed right now. Should it be open? Cant figure it out.