back filling water tank

[wingnut60]

Yesterday, wife heard water running while taps were off. Discovered that the fresh tank had filled and was overflowing. Have determined that the water supply is back-flowing thru the water pump. Understand there is a check valve to prevent this and probably has failed. Need to know where it is located. Only item not of plastic hose and banded fittings is a brass tee on the pressure side of the pump maybe 1 foot downstream of the pump. One leg of the tee is feed from the pump; one leg is feed from the filter/muny water supply; 3rd leg goes into the pex supply line that I assume feeds water to rest of trailer. Is this the check valve, or is it built into the pump?
Any help will be much appreciated. Many miles from RV shop of any kind, but can work off of water tank and keep city pressure off the system.
Thanks,
Joe
Pump is the 5.7 Smart Sensor, has worked well for the last 3 years. And plumbing is the original rats nest, not the manifold now in use.

[golf_bears]

Not sure about your pluming but when I ran into this same problem with our 2008 MS 36TK3 a few years ago I ended up needing to replace the water pump. It was explained to me that the check valve was built inside the pump and could not be replaced. The pump was under a 5 yr warranty so I was sent a new pump, replaced it and all has been well since then.

[Motor31]

Mine has done that on the odd occasion. I found that turning off shore water and just running the pump for a little bit seemed to stop the process. Perhaps it got a bit of grit or calcium lodged in the seal that allowed the back flow. You might want to try that and see if it works for you. We are still on the same pump since the rig was purchased in 05.

The check valve at the shore water hose fitting has failed on our rig. Right now I am just getting by with a hose cut off on the fitting when dry camping to prevent water loss. When we get set for a protracted stay I'm going to try and find where that valve is and replace it.

[Gemstone]

If your fitting is like this: City Water connection (http://www.rvpartscountry.com/CityWaterFlangePolarWhite), the check valve is built in. Easy to replace.

Regards
Gemstone

[wingnut60]

Gemstone,
If the valve is in the fitting, then that would not explain what is happening. A check valve there would only prevent backflow TOWARDS the shore supply. In my case, the shore supply is filling the water tank, and it has to go thru the water pump. Somewhere, there is a check valve I assume--have had the pump end apart and there is no apparent valve in the pump.
Thanks,
Joe

[Motor31]

Wingnut, Gemstone was talking about my water valve issue I mentioned.

BTW did you try running the water pump a bit to see if it reset your check valve? It does work on our rig.

Gemstone, that is the the one. I didn't reralize the check valve was built into it. Looks like an easy fix, thanks.

[wingnut60]

I may have multiple issues--water pump is now running more/less all the time, but not using water equal to time it is running. Losing pressure somewhere, but no apparent leaks. Also, if I turn on shore water, the water will back feed into the tank and overflow. It is now also raining enough to keep me from working outside, with not much hope for rest of day.
Still feel I need to find why the shore water is filling the water tank--is there a check valve in the pump itself? I have had the pump end apart and can't see how the pump itself can keep the water from going backwards.
Supposed to head for Anchorage today, so may be able to get some help there. Probably going to find out pump is at fault.
Thanks,
Joe

[rotaxman]

Joe,

Pretty sure your pump is bad.

As always good camping
Joyce and Jerry

[golf_bears]

Joe,

I will agree with rotaxman, you need a new pump. How old is the pump in your RV now?

If it's less than 5 years old, take it to any RV dealer and they should give you a new one at no charge. As I mentioned in my previous post, they are under warranty for 5 years.

"GET ER DONE"