4 dump handles

[sourdo]

Yup, I'm the proud owner of a used 2009 Forrest River Sierra 25RL 5th wheel RV. It's about 29 feet long with one slide.

And it's a unicorn. Even the insurance dude could not find any info on this thing. This was built back when nobody was buying RV,s. I think it's just something put together with spare parts, because I can not find anything for this model, no pictures, nada. 2008-9 was a real bad year for RV sales.

So that makes it difficult to find the answer to my question, why are there 4 sewer dump handles?

In the picture, you'll see the T, and the two gray water valve handles on either side of the black tank drain (two gray water tanks). And then there is the big black tank valve via cable.

But what is the function of the handle next to it? The one with no T handle. I tried to push it in, and bent it a bit. Since everything works, I'll leave it for now. But it's froze up.

I cannot find anything about how these things are laid out, like a schematic. Nor what the function of the 4th handle is.

Is it for directing heat from the furnace? It is all foamed up underneath.

Thanks for any info or clues.