Fresh water overflow from city connection

[Steven Mac]

I have a 2016 Winnie 25R. I plugged into city water and shortly after I had water dripping from my fresh water tank overflow. When I left the house, my FWT was 1/3 full. Now it seems that my tank is now full. I know I didn't plug into tank fill. My pump is off and I'm getting water coming from all faucets. Why, and how do I fix it?!

[be happy]

I could not find your rig in the list to see the plumbing diagrams.
https://www.winnebago.com/Files/File...m/Plumbing.htm

Do you have a separate connection to fill the FWT? and then a different one to attach hose to for park water?

If you only have one connection for the hose do you have a lever of some type that directs the water from direct to holding tank. If you maybe you moved the lever a small amount that would cause the incoming water to partially fill the tank. Only a guess however

I am sure folks with better knowledge of your plumbing will come on the help.
Welcome to the forum, for future posts it would be helpful that in the signature block you provide as much info about your rig as possible.

[Morich]

You likely have either a 22R or 25B? Possibly misreading a label for 25 B and seeing an R? Or I also type a lot of stuff that was not what I meant!!


I'm assuming that you were hooked to pressure water when the tank filled?

We can't be sure of the exact route but one common way this happens is easy to spot on the one I did look at,so let's pretend it is correct?
When we look at this drawing the pressure water is connected at the wet bay to the left, off the drawing but comes to the water pump.


The water pump of any brand will almost always have a check valve (red marks?) built in at the end and when that valve fails to close, the water can pass into and through the pump and out the other end where it goes on into the tank.
Instead of being pumped OUT of the tank, it flows IN?
The fix is often as simple as a small rebuild kit for the pump and it is an easy thing---once we get the pumpout! A few rubber gizmos?

Check for correct brand and models beforeusing these part numbers!

[creativepart]

This is a very common issue and almost always is caused by a leaking check valve in your water pump.

The thing to do now is to turn off the city water and use up the water in the fresh tank. Many times this is enough to correct the issue - at least for a long while. The check valve in your pump is a simple device and a small piece of sand or similar is enough to cause it to leak water through to your fresh tank. Using your fresh tank now can be enough to clear that problem.

This may not be enough to fix the issue, but is the place to start.

If you find this happening frequently you can order a check valve rebuild kit for a out $20 on Amazon and it’s an easy DIY project to rebuild it. Alternatively, you can install a new 1/2” check valve on the output side of the pump for a good forever fix.

There are other possibilities for this that would involve a city/fresh diverter valve failure if your RV has one of those in your utility compartment. But, I’m not sure if you have one of those or just a gravity fresh tank fill port. Not every motorhome has two ways to fill the fresh water tank.

[cruizerEd]

If your pump has a wintering valve that dumps water on the ground right before the strainer on the pump input open that. If water drips from it all day then it is your pump back flow valve is bad.

If you have a Shureflow pump be advised that some pumps have been redesigned and the backflow valve will not fit even though it has the same part number.

Even if you can replace the backflow valve it may not last long, mine only lasted about a month and then it started leaking but very slowly not enough to fill the tank, yet.

Probably best to put a reliable backflow valve on the output of the pump.

Not sure how much you use your pump but if it is sounding noisier than you remember it is probably going bad anyway and you might want to order a head or a whole pump.

[bostonmary]

Hey, I had this issue on a Holiday Rambler. It started when I accidentally turned on pump when hooked to city or shore water. I fixed it by turning shore(city) water off, cycle pump, turn pump off then back to city hookup. Then it started happening on its own. The cycling worked for about 6- 8 months. Then I disconnected pump. Would like to know more about exterior check valve. While I am here did Winnebego put low water drains on their tag alongs? Particularly the 2108 (2018)

[Morich]

Exterior check valve? Many times it is simple to just cut the line and add an inline check valve, rather than pull the pump and change the one it has built in.
Part of the added benifit of the inline chack valve is the ease of finding one and the price as it then becomes a simple big box/hardware item instead of an comparatively expense Rv specific item!

Since size of tubing or pipe is the main thing to shop, one easy way to go is to decide where you will place the inline, snip a small section like half inch out and take it to the store with you.
Buy one to fit and it likely fills the small gap you cut out! Make sure to turn it the right way for water flow!!
One step safer than trying to measure and guess what the inside diameter might be?