All I can add is that some RWs are not plumbed properly. Last spring we had to change our Hot Water Heater because it sprung a leak. I thought I could use the By Pass to by pass the heater and still have water in the RW but it was a no go. The way ours was hooked up we were actually getting some hot water mixed with the cold in the Wet Bay.
Michelle & Ann
2018 Chevy 3500HD Crew Cab High Country DRW, D/A, 2016 RW39MB, Dual ACs, Auto Level, Auto Sat Dish, Stack W/D, King Sleep #, 17.5" Sailuns w/Disc, MORryde IS & Pin, Comfort Ride Hitch, 5.5 Onan, Res Fridge & Induction Cook Top