On board water tank

[61851]

When I'm hooked up to city water my onboard fresh water tank fills up.

[Lv2Roam2]

Welcome to the group! Check your water fill valve (usually located in the same compartment where your water hose enters the RV). The valve may have 2 positions like 'normal' and 'fill tank.' That valve needs to be on 'normal' when using city water.

Sometimes the valve will be stuck open with debris. Try flushing water through the valve, and while doing that - cycle the valve back and forth a few times.

It is also common that these valves fail. The average DIY person can replace the valve themselves with some simple tools.

Let us know how it works out ...

[61851]

I've tried switching the valve back and forth and it still fills the fresh water tank I'll try taking it apart. Thanks

[Morich]

More info on the RV is always helpful as there are dozens (hundreds?) of different ways to get it done. Year, make model, etc. gives much better chance at correct answers.
One really good resource for info on your specific RV can be found here:
https://winnebagoind.com/product-res...ct-information
Tons of info down to and including wiring and plumbing diagrams for motorhomes, so knowing what you have cuts the chase a while bunch! Also manuals for your unit are often online and give you a chance to read up on questions that they book may cover.
Enjoy the RV but it can take a bit to get the hang of things.

[61851]

Ok it's a 2019 minnie plus 26rbss

[Morich]

Originally Posted by 61851

Ok it's a 2019 minnie plus 26rbss

Okay! Sorry, I tend to think motorhome, rather than trailer as there are so many more complex things to watch. Let me do some reading/looking for manuals. Do you happen to have one on hand? It might give some really good help-- or not! Sometimes I find they seem to miss telling me small points as if EVERYBODY knows that stuff.

Just did a look at the manual and don't see any help. One small point, I did see that you might need to know if no manual on hand, etc.
This note is in the book:
NOTE: As long as the water system is hooked up
to a city water supply, the onboard
storage tank and the 12-volt pump are
isolated from the system. Do not turn the
pump to “ON” until the city water supply
is disconnected in order to avoid damage
to the pump.
On a 2019, I might guess it is new enough to go back to the dealer for repair? But then, there are always times when that might not be too handy and I would want to sort it out myself.

[61851]

Travel trailer don't come with a manual. I sure wish they did. You can't even look anything online. At least this one didn't and I can't find anything online.

[powercat_ras]

Depending on your TT, you may have separate water tank fill and city water ports and no CITY/FILL selector switch at all! So ...

Another reason that your fresh tank can fill up when you connect pressurized water to the city water port is that water is back flowing thru your water pump. There is a check valve inside the pump that is supposed to stop this , but it may have failed or just have some debris trapped in it that is preventing it from closing. You or someone can remove the water pump and fix or replace to resolve. If you want to try it yourself you can get service information from the pump maker's web site or find youtube videos.

One thing that could help minimize that back flow is to make sure the city water port water pressure is regulated to 40 PSI or less, to put less strain on the pump check valve, plumbing connections, faucets, etc. Good luck.

[61851]

It does have a switch on in coming line for city water or to fill the freshwater tank. I do have a pressure regulator on it.

[Lv2Roam2]

If you have a built in 'antifreeze pick-up hose' for winterizing check to see that its valve is turned off while using the water system.

BTW: with such a 'hose' its often possible to fill your water tank using the water pump by placing the hose into a water source - really helps when boon docking.

[luvlabs]

Your water pump also contains a check valve and that is often the point of failure. You can either rebuild the pump or replace it. Pump check valve failure is more common than the valve failing.

[RTrider]

I have experienced the back flow through the pump. When it first occurred, it seemed to happen after there was a water "failure" at the campground and when it came back on, the fresh water tank would slowly fill. If I turned of the water and ran the pump, and then slowly turn the water back on, the problem would resolve itself - until next time. This occurred off and on until the pump failed. When the pump was replaced the problem went away. I understand this is a common occurrence.