Confusion and my Water Holding Tank

[Bethers]

Posted this on FB also - so some of you might see this twice. I am totally confused -

OK, left the rv just before 5:30. Returned at 8:15. Walked up to the door and noticed the ground from the door back a few feet and for a bit under the rig was saturated. When I left the fresh water holding tank was about 1/3 full. No hose was filling that tank. After checking everything out, the fresh water tank is FULL and the water is from overflow. How in heck? My hose was still connected to the water inlet for direct water. I turned the water off - turned pump on and ran water till the holding tank shows 2/3rds. Totally confused. I mean, what the heck? Why would someone fill my holding tank? It makes me nervous. I just might have to totally drain that tank and clean it out. I can't figure anything else out???

[Acadianmom]

I don't know how all that works but do you think maybe there's a valve in the water system that failed and let water go into the tank?

Martha

[snowball]

don't have a clue but like what Martha said
sheila

[Bethers]

I don't know how all that works but do you think maybe there's a valve in the water system that failed and let water go into the tank?

Martha

I was told they are totallyy separate in this rig. But I'm guessing maybe not. But the connections aren't even near each other. I'll be calling service, that's for sure.

[Irmi]

Beth, I found this on RV.Net:

Fresh water tank filling by itself

We recently upgraded to a new to us 2002 Sunny Brook Mobile scout. I emptied the fresh water tank about 1 week ago using the pump. Today I noticed water coming out the overflow on the fresh water fill compartment. We stay on city water all the time, I have a 40 psi regulator as we'll. the only thing I can imagine is the water is back flowing through the pump in to the fresh tank, and slowly. I would have thought there would be a one way valve to prevent this? Has anyone had a similar issue? I do have a valve next to the pump I can shut off, but I would have to remember to open it every time or you can burn the pump up.

[BirdbyBird]

I am thinking that CArol had a funky fresh water tank/pump issue recently, also. It involved a faulty valve......Waiting for CArol to chime in.....

[retiredhappy]

Beth, on my Roadtrek there is a handle I can turn on when I'm hooked up to city water that diverts the water to my fresh water tank to fill. Once its filled, you turn it off. Do you have anything llike this on your rig?

[chalet05]

My handyman says probably a check valve in the water pump.

[Bethers]

I did turn on my water pump briefly - very briefly - yesterday. So I think that is probably what caused this - and that valve. I will be reporting it to the dealer. I was so shocked last night!

[JudyJB]

I had almost exactly the same thing happen to me last winter (2013) when I was parked in Las Vegas. I was hooked up to city water. My water fill for my fresh water tank is completely separate and on the other side of my rig. I went to bed with only about 1/3 of a tank of fresh water that I use when I drive. I woke up in the morning to a knock on the door telling me that they had turned my city water off overnight because I had a large puddle under my rig.

Turned out a diaphragm in my water pump had sprung a hole. Somehow, the diaphragm prevents water from filling my fresh water tank, so when the hole appeared, it filled my fresh water tank to overflowing. And at that point, the overflow valve on my fresh water tank that I did not even know I had made the puddle. Water pump was NOT turned on.

So now, I had no usable fresh water, except my fresh water tank was not 100% full, but I could not pump any of it to use because my water pump would not work. Nor, could I use any city water or I would have another flood!! SO, I made a bunch of phone calls, unhooked and headed off to get a new water pump installed. Solved the problem to the tune of over $200.

Funny, but someone on another forum posted about this exact problem, but this was a man, so I know it was not you.

[MelissaD]

This is a basic RV fresh water system. Normally the city water is separated by a check valve which maybe separate or part of the pump assembly. Basically you have a ruptured diaphragm as Judy said or a leaking check valve which is allowing you to back fill your FW tank.

[Bethers]

I guarantee it's not ruptured and it's no longer leaking or it would be filling the tank again and/or still overflowing. And the water pump still works on it's own. I do believe it could have been stuck open - which is also what a service tech told me - and he also told me it may never happen again. Ha. I'll be at the dealers Thursday and they'll check. They told me if they can't get it to fault, it may have been a fluke. Flukes are known to happen in my life, so wouldn't be a first time.

[longdog2]

It's nice when it's a fluke because you don't have a repair to pay for BUT then you keep waiting for the other shoe to fall so to speak. lol

Thanks for the schematic of the water system Melissa. Helps all of us to have a visual. Since my RV has a control panel in a compartment outside and the connection for both the city water hook-up and the fresh water fill are the same, I suppose I have more valves. I have switches fresh water fill, city water, sanitizing fresh tank, sanitizing lines, and winterizing. It took me a while to figure out that "Normal" was to utilize the water in the fresh water tank. And more than once, I have panicked because I hooked up to city water and didn't get coming out of the tap until I remembered that I had to turn the switch over to city. I put it on Normal when I travel so I can use the bathroom and sink when I stop during the day.

[JudyJB]

Thanks for diagram. That is exactly my setup except for the water filter once the two fresh water lines join.

Hoping for the fluke so you don't need to repair anything. Sort of like my theory about things fixing themselves if you give them enough time.