The problem is trying to find them. The bypass valves are usually located behind the WH as shown in the image turbo posted. There should be a removal access panel under a cabinet, in the pass-through, somewhere very close to the WH. The factory tries hard to hide them, but we usually find them.
On some of the new campers, the bypass valves are in the camper's docking station.
Nights camped in 2013 - 55, 2014 - 105, 2015 - 63