Here is the full story....
1) Not long after taking delivery my sister and brother in law spent a couple of nights in the coach. I was new to the rig and whole hook up process. I mistakenly connected the shore water to the tank rinse instead of the "city water" line. I did have some water in the fresh water tank and the pump was on; (I know better now but I was new to all this at the time). They called me (several times) to come over and dump the grey tank which they kept an eye on at my instruction and seemed to be filling faster than the water they were using. I realized my mistake when I closed up the coach but never did question why the grey tank was filling so fast. Thought they were using more water than necessary which they denied. Clearly they were using little water but what they used came from the fresh water tank I had left partially filled with the pump on. The rinse was filling the grey tank which took some time since the grey tank is larger than the holding tank.
2) Months later I did use the rinse one time after draining both tanks but just did not notice that it was the grey tank that had a continued water flow, probably had both valves open at the time. Again did not consider that I might have a problem with the rinse function.
3) This weekend we filled the grey tank twice and each time I let a little out (full hookup site) so that when I did dump the holding tank I would have a nearly full grey tank to flush out the hose.
On closing the coach down I first turned on the rinse with a holding tank about 60% full and draining. (grey tank is closed and full at this time). Within a moment I had water draining all around the wet bay; obviously something was wrong. I shut down the rinse immediately and checked inside the coach. The bathroom floor was wet, the hall was wet and water was leaking out from under the kitchen sink. As the wife cleaned the bathroom floor she said it appeared the water came from the shower. It was wet from spray; toilet looked entirely normal, no water or debris inside the lid; I checked and did not suspect the rinse problem as yet. Actually I thought I had a broken water line from the rinse hookup.
Cleaned up the water (no odor of any consequence and it was clear water; no dark color, or blue color from the toilet chemicals I use). After we cleaned everything up and the holding tank had been drained I hooked up the rinse again and turned the water on slightly, (grey tank is still full). Wife inside coach gave out a yell and I turned off the rinse.
Water out of the shower drain again, and from under the sink (where I found a vent pipe attached under the cabinet running up the inside paneling). This is where the spray was coming from according to the wife who pointed at it while I held a flashlight on the vent. She had seen it spraying out.
Cleaned up again and drained the grey tank. Did not reconnect the rinse hose.
Even though the rinse was on only a minute or two, I did have the holding tank valve open while the grey tank was closed and no more water came from the holding tank.
Can you imagine any other explanation for these experiences? How otherwise, would turning on the rinse cause water to spray out of the shower drain or come out from the vent under the sink?
Gary, Cindy, Reacher (Maine Coon), and Vivian (in spirit only now).
Retired: July 31st, 2013 and loving it.
2011 Coachmen Encounter 37 TZ pulling a 2012 Wrangler Unlimited Sahara. Many upgrades, additions, mods, and changes.