Gray water valve questions


Well-known member
Last year we had the gray valves replaced in our 2011 Landmark. At the end of the season this year we again had issues with the valves. In talking with the tech he said he found debris in the path of the bath valve preventing it from closing all the way. In thinking about our conversation since then it occurred to me that the only debris that would normally be introduced to the system would be thru the black water tank. How could that debris interfere with the gray water valve? In November when we went to the dump station I believe some black water made It past the that gate in addition to the bath gray tank being already empty. So some of the mess that came out before I opened the gates to dump probably was that mix. Another factor was that it was used as a backup trailer for our family campground accommodations so it sat unused for weeks at a time. I guess what might help my understanding is if someone can explain the way the 2 gray & the black discharge piping come together & where the respective gates are located. I tried to google the tank discharge pluming diagram w/o success. Thanks

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Well-known member
I tried getting a diagram for mine, and was told by Heartland that they don't provide diagrams for electrical or plumbing. You're bound to get some replies here telling you to call them with your VIN and maybe you'll get lucky. I didn't. But plumbing is usually pretty easy to trace in fifth wheels because the floor holes are usually way bigger than they need to be for the pipes (sealing them against rodents is a common new-owner task) and fifth wheel frames usually have a ton of access holes all over the beams.

Try getting an inexpensive USB or Wifi "borescope" off Amazon. I got and while I sure wouldn't call it "amazing" you get a lot for forty bucks. I've used it for all kinds of tasks between electrical plumbing and mechanical. You can pair these with your phone so you don't need anything else to use it, although it does take some practice to understand what you're looking at (the cheap ones don't have much "depth of view" so you often have to get close to things to see them well).

I've used this twice to avoid dropping the plastic underbelly cover. You can pull just a quarter inch of the underbelly down to make a small gap and sneak the borescope in there. If you do this near where a black/grey line goes into the underbelly it's usually pretty easy to trace those out. This is a nice trick too for finding things like where to cut access holes to fix broken "remote valves" (cable operated).