Unwanted Fresh Water Tank Fillup

May not be the regulator though. Our FW has just started to do the same thing and found about 1/3 of a tank full a few days ago.

The water pressure at one of the CGs we visited this season had 120 psi. Don't know which one but we have a Watts regulator installed inside so I know the tank didn't take on water due to high pressure.

Also, have never used the FW tank so I know it's not due to sediment buildup at the pump check valve. Check valves they use probably just aren't the best of quality...

I will probably just install a new check valve at the FW pump end of things. Will use a good quality commercial grade one too.

We always have used a pressure regulator, but it's possible maybe it was somehow still a hair too high and that caused it. Or possibly when I first turned on the water supply at hookup it rushed in too fast and caused the issue? Just guessing there, not even sure if that's a possibility lol....

Either way, next time we hookup (we go to the same campground pretty much all the time, same site too) I will turn the water on a little slower and see if that even matters.

I had that problem. In my case it was water pressure being to high at some parks. I bought a water pressure regulator to fit my hookup hose and problem was fixed.

I'm guessing it must have just been the vibration from towing our TT in and setting up on Tuesday. I drained the fresh water tank about 24 hours ago and so far it hasn't filled back up yet. I'm guessing water deposits (like was mentioned earlier) combined with a little vibration teamed up to leave a small gap that apparently has now closed.

Thanks for all the tips!

Mine was the divert valve also. The O-ring came loose

my bounder had a small brass valve to divert water to tank or system. there was a very tiny crack in the O ring that let water fill the tank in error.
bumpy

@ TusconJim - no we don't have a "Kantleak" panel for water management. Thanks for the reply, though.

@ TUCQUALA - We rarely use the pump, just maybe once or twice a year to winterize and de-winterize. Thanks for the tips, I think you are spot on. Same thing some other buddies have said.


@ CA Traveler and Oasisbob - Once again yes I think that may be a part of the issue. We do ru a pressure regulator though each time. Never hook up without it.


@ Old-Biscuit - That's what I will try, especially if tank starts to slowly fill again on its own. I was always curious why the pump wouldn't run when that happened, but I just quick-checked it without relieving pressure from city water conn. I will turn off outside supply and open the faucet til I get air, then try the pump again. Even if it doesn't refill this trip, I will do that when I get home just to run the pump and try and clean it off a little.

Thanks to all of ya'll again for the tips. Much obliged...

RV water pumps have an 'internal' check valve (diaphragm that stops backflow thru pump)
When pump is not used often the diaphragm can leak allowing water from 'city water' to flow thru pump into fresh water tank.

Running pump can 'cure' problem by allowing diaphragm to clear off any debris and reseal.

Pump will only run when line pressure drops below pump pressure switch set point

3X on the check valve. Do you run a pressure regulator? If not could this be a piece of the puzzle?

You have a leaking check valve which may be part of the pump.