My fresh water tank filled itself up!!

[delongboy]

We got our new to us Jayco last summer and used it a handful of times, mostly on weekends. This year we took it on our first week long camp out. Everything was going great until about 5 days in when we woke up to a wet carpet in front of the door. I checked all around the door for leaks and couldn't find anything. I then traced a small trickle of water across the floor under the couch and what appeared to be the outside wall on the opposite side. I check under the sink for leaks and found nothing there.. I then determined maybe it was coming in from out side so I went out to investigate. It was then I noticed water coming out the fresh water fill inlet. I took the cap off and water started coming out.
Now I usually keep a couple gallons of water in the fresh tank for potties breaks along the road and what not. But not full like this. The only thing I could figure was the water was feeding from the city hookup past the water pump and in.
I closed the valve from the water pump to the tank and it fixed the problem.
But now this concerns me. I don't believe this is normal? Is there a valve on that side to only allow water one way? Or does the pump handle that? If so, is my pump shot or fixable?
Also, shouldn't there be some kind of overflow from the fresh water tank that doesn't lead back into my camper?
Any advice appreciated.

[3'senough]

My unit has a service panel for this type of filling like country fill using the pump or city fill. It's the only way water can get into my tank. Being that your unit is over 7 years old your impeller blades could be missing or shot and it needs replacing. Water can push past this if they are not sealing right. You might also look into instaling a check valve before the pump from the tank to prevent it from happening again.

As to the outside leak on the inside the pressure probaly built up and pushed past the hose clamps behind the walls since they are not ever really under pressure and need to be tightend due to years in service.

[RoyBraddy]

Consider this simple diagram of the water flow in a typical RV trailer...


For the water from the site city water spigot connection to get to the fresh water tank it would have to go through the trailer water pump as well as the ONE-WAY valve between the 12vdc water pump and the fresh water tank.

I have never experienced this with my setup but have had water come out of the city water connection one time when I was running the 12VDC water pump. I smacked the one-way valve shown on the simple diagram between the 12VDC pump and the city water connection and it stopped.

The only method I have ever used to get water in the fresh water tank on my 2008 OFF-ROAD POPUP trailer is to pour it in myself at the fresh water fill spout.

I have seen some folks mod the system to include a bypass using tee's and another valve to allow the city water connection to fill the fresh water tank. I don't think I would ever do this mod as the pressure of the city water may exceed the over fill port and crack the fresh water tank by having too much water pressure in it. That was an actual recent report on one of these forum.

[delongboy]

Wow.. great diagram. So there should be a one-way valve between the pump and the fresh tank? I will have to look for that and probably replace it i'm thinking. It must not be closing properly.. It must be only a little bit getting through because it did take 5 days to fill the tank.

PS. I do have one difference from you diagram in that I have a valve between the pump and fresh water tank that I can switch to a small hose for the purpose of using the pump to winterize the camper with antifreeze.. This is what I closed to fix the problem. I was wondering if this was designed so that when not using the fresh water tank you have to close this valve?

[rescuebub]

I think alot of pumps have the check valve built into them, so you may not see a seperate check valve in that line. You may need to replace or rebuild the pump. The tank should have an overflow, but as stated above, it may not be large enough to handle the flow you had going into the tank.

Good luck and happy camping!

[mcfarmall]

The pump has an inlet and outlet check valve built into the pump head. Probably a piece of dirt or plastic shaving stuck in it.

[delongboy]

I'm thinking my overflow line may be clogged. There was nothing running out when I checked. And it wasn't filling up that fast. It took 5 days to fill the fresh water tank from almost empty.
I may be leaning towards mcfarmall's idea that something is stuck in the pump causing the valves to not close.

[Bob in Mass]

All of the above is great info. Do you have a pressure regulator of some sort between the city water source and your trailer?

Too high a pressure could possibly squeeze past a check valve, if older, sediment, etc.

[delongboy]

Yes, I always use a pressure regulator on city water.