Cougar 22mls

There is likely a panel inside the trailer with two screws holding it on that needs to be removed to find the valves. These valves are located on the (front) side of the water heater, not the back side (which is visible from outside the trailer) - that is likely why you don't readily see the vavles.

Should be a single valve or a triple set of them right in front of or behind the water heater. I have never seen a bypass located in any other location other than right around the heater.
Barney

Single valve bypass


Two valve bypass


Three valve bypass