Well, this weekend proved to be an 'interesting' event. Let me prefix this by saying that I've learned my lesson:
Do not leave a hose hooked up to the black tank flush and just 'trust' that nobody will turn the water on.
So, time for the story:
Yesterday morning our tanks were full, so I dumped, flushed, etc... to have room for the rest of the camping trip. We were only staying one more night so I didn't bother to unhook the x-hose I use for the sewer flush. I just turned the valve to shut off the supply. I figured the next day I'd be able to just turn it back on when I flush the tanks a second time.
Later that night I was just getting some dinner cooking on the outdoor stove when my wife stated "Where's that water coming from?". Never a good sign to hear that. It appeared to be coming from the bathroom, which my son had been in just a short while ago. Since we've already caught him once closing the drain in the sink and then leaving the water on, I assumed he did it again and it overflowed. Great! Just what I need to deal with.
While, since I was getting the food going, my wife decided to go in and check on it. From inside the trailer I hear the scream "Shut off the water! We've got a geyser!" I immediately flip off the gas supply, run around the trailer and kill the water at the tap. I then fly back into the trailer, shouting at the kids on the way to remain in their chairs and not go near the stove. Bolting into the bathroom I ask my wife where the water was coming from.
I was not expecting "It blew up from the toilet when I tried to flush." From inside the bathroom to outside, around the trailer and pulling the black tank dump valve in about 0.2s. Bawoosh! The force of the blast coming out pushed the RhinoFlex out to full extension of the slinky! (Here's where I give thanks to having a Rhino. I don't think a cheapo hose would have held up to that pressure.) Now I look over and realize the x-hose's valve is sitting at a 45, instead of fully shut.
Ah, so that's what happened. Somebody touched the valve, turning it on, and it filled my black water tank. After disconnecting the hose I headed back inside and was able to confirm with the wife that it was, indeed the toilet that threw the geyser. She was trying to determine where the water might be coming from and had opened the valve to see in the tank. As soon as the toilet valve was opened that freed the pressure by forcing the water up and into the bathroom.
So after a very disgusting, but very through cleaning of the whole trailer. (Thankfully we have disinfectant as part of cleaning arsenal) we managed to remove any sign of the water. During the cleaning, I was able to determine that the water dripping on the outside of the trailer was coming from the wheel wells, where the bathroom sits, and not from the underbelly, where the black tank sits. Since we have an enclosed underbelly, I wasn't able to see the tank itself unfortunately.
All cleaning done, we got the trailer put back together, I throughly scrubbed and then finished cooking a now cold dinner, and we ate outside. After dinner, showers (in the campground's facilities) and getting the kids off to bed, I was able to stop and think a bit about what happened.
Aside from the possible water damage, I'm concerned about 2 other things:
1) Where was the water coming from? I assume it was being forced out from between the tank and the toilet but not having seen the bathroom pre-flush-geyser I don't know. I might have a ruptured black tank, but the fact that it was leaking from the outer edge of the wheel wells instead of the enclosed underbelly gives me hope that I'm fine.
2) Why was the system under pressure? If I understand RV plumbing correctly, the water should have had an escape route via the vent in the roof. I checked the roof this morning, but didn't see any sign of the water being up there. Why didn't the water come up and pour out of the vent?
Being a holiday weekend, my dealer was closed, but you can bet that I'll be calling and booking into the Service Department first thing tomorrow morning.
So there's my "I never thought it could happen to me" story.
Hopefully my experiences help save some of you out there from the same fate.