Yes, those three valves are in the manifold compartment located on the passenger's side of the coach. I failed to mention in my previous post, that there are also two pop-ups in the compartment that houses the sewer and water connections on the driver's side of the coach. And with the two for the tank, there are seven pop-up drains.
My fresh water tank is directly in front of the manifold and it extends the full width of the coach. On each side of the tank there is a pop-up drain. Mine are readily visible when you open the compartment doors on either side, so I would assume that if you don't see them, your coach either doesn't have them or they are elsewhere.
I would hope there would be a drain somewhere. Unless your coach is parked at just the right angle, I don't see how you could possibly get the tank completely empty when sanitizing it.
'03 41' Friendship & 24' trailer with HIS '03 H-D Heritage Springer, HER '15 H-D Freewheeler Trike, and '08 Smart Car.
"Adventure is found in the journey, not the destination."