Fresh water tank filling by itself

[Jwestman]

We've been out for 10 days hooked up to fresh water with both an outside filter and water pressure reducer. This is a 2012 25FB flying cloud. Checking the tanks tonight I discovered that the fresh water tank was almost half full. Since we left home empty, I thought it was a mistake but when I opened the drain valve on the tank sure enough a steady stream of water is coming out. Is this normal? How does the water get from the "city water" side to the tank?

Thanks for any help and thoughts. j

[Al - K4GLU]

Bad check valve in your water pump. I've had that happen twice. Hope you're still under warranty.

[rmkrum]

There should be a check valve near your water pump outlet to prevent water from going 'backwards' from the pump to the fresh tank when city water is connected....or it could be missing. Some pumps have the check valve as part of the pump.

Right past the check valve, the city water connection should join your piping to sinks and the rest of the system. typically there is a 'tee fitting' somewhere in that area. There is also a check valve in the city water fitting as well, so the pump won't dump water over the side when it is running...

The valve could need replacing or rebuilding of the internal seals if it is repairable.

[Jwestman]

Wow! You guys are quick!! Thanks so much. I have my last appointment before warranty expires on Friday. j

[pmclemore]

Glad you found some good reliable help. I was afraid someone had slipped some dehydrated water tablets into your tank while you weren't looking.

Pat