Good morning, this rig has two black tanks. In addition, inside the compartment there are two black tank flush connections. When I hook the hose up to one connection it appears to be flowing appropriately. However, when I connect to the other water shoots out of the unconnected inlet. I’ve checked the valve located in the shower, thus far can only find one valve to ensure that they’re connected appropriately. The one does appear to be connected appropriately that’s located in the shower. If there is in fact another valve I cannot find it.