hot water tank
I installed valves from marinetechgroup, down in my bilge and I am able to winterize all of my systems through them. I open the hot and cold spickets until they turn pink, then turn off the cold, to make sure the pink come out of the hot spicket side.'
Been doing it like this for 4 years and no problems so far.
These valves enable me to winterize and get it done very quickly and if I want, I can use the systems, then just run antifreeze through them again.
Jeff Drury