I have a 2016 Class-C by Coachmen. Our 2008 Freelander had what I thought was a great set-up from the factory with suction or fill tank or city water selected in a "water box) and three valve handles.
The 2016 now requires me to empty my basement storage and after climbing in I have to remove a wood panel that is 5' long then try amd move multiple electric cables to get to see the water pump.
The FR instructions wants me to disconnect the inlet side of the water pump and then make a suction line to suck antifreeze into some of the water lines.
I know I could install a special valve but I still am concerned about having many feet of water line that is not protected.
Here is what you system seems to be. Note I believe there is a check valve between the pump and the line that goes from the city water inlet to the various sinks etc.
My concern is that line A & B which are maybe 8' long will have no antifreeze protection. Also Line C at about 4' has no antifreeze protection. I really don't want to have to somehow get antifreeze into the Fresh Water tank. This isn't mentioned in the instructions from FR.