[A/S] damp area in my 34' er

[Tom Cook <cwent@xxxxxxxxx>]

My new to me 1992 Excella with Queen rear bed has a valve on the floor
inside the street side nightstand. There is a layer of plastic still on
the floor and the carpet under the plastic is damp inside and just a few 
inches outside of the cabinet. But the valve does not appear to be 
leaking. Any ideas??

And can anybody please tell me what this valve does ?

Thanks.

Tom