I have a 2016 Grand Design Momentum 349 Toy Hauler.
There are two 2" fresh water dump valves. These valves are visible. There is also a 3rd valve handle that disappears into the belly, at the tanks. Can anyone tell me what this 3rd valve is for? Possibly transferring water between tanks?
Never argue with an idiot. They will bring you down to their level, and beat youwith experience.