'city fixture' is now filling water tank?

[BigSarge]

This just happening for first time...while hooked up to city water tap @ campground and with my 'Anderson Brass Kantleak' selector in the 'city fixture' position, my onboard tank filed quietly in the night and the overflow caught my attention in the morning.

A possible leaky internal valve allowing water into both my RV fixtures and on-board tank?

[bevedfelker]

Happened to my Vegas. I turned off city water and ran my water pump for a while. Cleared the problem. Was probably a piece of debris lodged in the water pump's check valve allowing water to reverse flow through the pump into the tank.

Drained the tank. Turned city water back on and haven't had the problem repeat. That was 4 camp RV parks ago.

[brianh442]

Do you have a water pressure regulator on the city spigot? If so is it adjustable? I had that problem last month at a campground. Last used last year was at a campground with very low water pressure. I had the regulator adjusted to up the pressure a bit. First use out of the gate this year was at a park with good high pressure, actually park was almost empty, so very little demand, hence high pressure. I noticed my rig was starting to list to the right, bathroom door swinging, that was first clue. Re-leveled coach but later noticed it was noticeable listing right, what it looked like when I filled my fresh water tank with 100 gal of water for dry camping.

To my surprise when I looked at my fresh water tank it was almost full!! I only had approx 20 gal when we left home, just enough for traveling, washing hands, flushing toilet making ice etc. When I checked my adjustable regulator is was up over 70 psi. Yikes, I immediately lowered it to under 45 psi, where I normally have it, drained the tank back down to less than 25 gal and haven't a problem on the current trip we are on.

If that's not an issue then it may be a check valve that's failed!

[BigSarge]

Thanks to all for your input. I received an email reply from Anderson Valve themselves...it seems it may be an unlucky occurrence as this is the reply I received:
" It is unfortunate to read that you are experiencing a problem with our 4 function water distribution valve. We’ve developed a repair kit just for situations like this and if you would provide me your mailing address, I would be happy to send you one free of charge."

I will switch out my pressure regulator as well and monitor things for now.