Valve for the Black Tank

[Bulldog]

2011 Montana 3400RL. I can’t find the valve that prevent back flush for the black tank. Looked under the bathroom and kitchen sinks. Where else may it be.

[jimcol]

Look in the wall that your shower faucet is on. Not sure on your model but on some they have had to cut an access hole in the back of the closet behind the shower. Others have been lucky enough to find a plastic cover in the closet that exposes the backflow valve.

[beeje]

Remove the white plastic cover behind the convenience center and follow the pipe from the flush hook up. The pipe will go up into a wall, along with the other end going down into the tank. You can cut them in the basement and plumb them together.

[DQDick]

Some years, when they had a bathroom that backed up to a kitchen cabinet they had it in the wall behind the cabinet with an access hole there.

[Carl n Susan]

Check out this Thread for the location of the back flow valve on a 3400 and how to access it.

https://www.montanaowners.com/forums...ad.php?t=39046