you should have a water heater bypass. should be right next to the WH.
it's so that when you winterize, you don't get a bunch of antifreeze in the water heater.
you don't want antifreeze in your FW tank nor your WH.
and Zoe the Wonder Dog(R.I.P.)
'07 Roo 23SS pushing an '07 Chevy Avalanche
Equalizer WDH and Prodigy BC