My Viewfinder has two water inlets one of course is the fresh water intake and the one above is what I think is the black tank flush valve (not marked). Problem is I have ran water thru this and it does not seem to get to the black tank. I asked before and someone suggested it may be kinked so I tried to follw the hose from under the sink and it goes toward the shower and can't see it after that. Anyone have a suggestion of what to do next. I guess I can open the frame cover and look there but I hate to "break" on seal that keeps the cover from allowing anything inside the cover and the frame.