I too have a 95 T and a 2209T the fresh water tank is larger than the gray water tank, it is possible to run the gray water tank full, especially if you are hooked up to a water supply. The next lowest point in the system is the shower tube and the gray water will back up in there. When you look into the tub drain you are looking into the water trap and you will see water in it, even after draining this is normal. All RV trailers have a similar problem. You have to use as little water as possible when washing dishes, to prevent over flow, unless you are hooked up to a sewer drain.
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