Fresh Water tank filled up when hooked to city water

[Pugfug]

Good Morning all,

Thought I'd relate an experience from this past weekend regarding a water issue that we had to get some feedback from others. Last weekend, after dewinterizing our Keystone Outback 25OURS, we discovered that we had water leaking from the side of our unit around the fresh water fill up cover. After some investigation, we were surprised to discover that our freshwater tank (which we have never used) was full and overflowing, even though we were hooked up to city water. We have a pressure regulator on our line and always have...

After some trouble shooting, I came to the conclusion that one of two things had happened....first, we thought that maybe a valve inside the water pump had stuck open, perhaps from the winterizing process at the dealership...though in my mind this seemed unlikely as we've never used the pump or the fresh water tank...and we were pretty sure that the dealership did not either.

Second, the pressure in our water line may have "spiked" thus forcing water back through the pump and into the fresh water tank...So I went outside to check...the first night our pressure regulator was reading 45psi after hooking up to the water at our RV park...by the next morning the gauge was reading over 60psi...

I think this was the culprit, and so I added an additional pressure regulator to work in tandem with the first....this seemed to eliminate the problem. H

Has anyone else ever experienced this? I'm thankful that there was no apparent damage to any of our lines...everything else is functioning properly and no more issues with the tank filling up...

Thanks

[sourdough]

We've not had that issue but my question would be what kind of pressure regulator are you using? Is it adjustable with a gauge or?? If you set it to 45psi and it just increases to 60psi on its own, I would call that a malfunction and replace it instead of putting a 2nd regulator on with it. If the first one does't "regulate" it's just in the way it would seem.

[Bechard]

I just had the same problem, while using a pressure regulator, and it was my Flojet pump. The backflow in the pump went. I just got the call from the dealership that it's all done and replaced under warranty after dropping it off two days ago.

[AbHDToyHauler]

My trailers convenience center has a switch which says city /fill and if in the fill position will fill my tank?? While only in city position will use city pressure and bypass my pump.

[bobbecky]

Water pressure from a city connection is always pushing against the check valve in the pump, and if the check valve is not working, water will go through the leaking check valve and fill to overflow the fresh water tank. You either have to replace the pump, replace the check valve, or install an inline check valve on the city side of the pump.

This is a check valve installed on the city side of our pump after a check valve failed on our pump. The pump has since been replaced but the check valve stays installed.