Freshwater tank fills when switch is off

[ptblues2]

2021 Wildwood 31KQBTS pull behind travel trailer
The freshwater holding tank is filling and overflowing when the interior switch is off. We have drained the tank and it filled and overflowed again. The only way to stop the wasted water was to disconnect the RV water supply.



The RV was just brought home from the repair shop. Could the repairman have turned a valve? Or bumped something? I called them and they want the RV returned for a look over. Good grief! Does anyone have any thoughts on this?

[NMWildcat]

If you have it hooked up to city/shore water source, there is no need to run the onboard pump (interior switch) as it can cause problems with check valve in the pump resulting in your exact problem.
Do a search for reset of pump check valve or fresh tank filling. There are hundreds of posts about the problem and how to reset the check valve.
And it is possible that if you have the multifunction water valve panel type, they are not set correctly, but you should be be able to match the valve setting pictures with the desired function.

[SeaDog]

welcome to the forum its a great place to get your questions answered. this happens often when the check valve has stuck open on the pump.