INTERIOR WATER LEAK

Hope you have fixed your problem. The std check valve's associated with sinks are designed to keep gray water fumes from entering rig - not to keep bacteria from entering fresh water system.

Mystery Solved! And I'll give you a bit of information regarding it in case you come across this problem.

There is a valve under the sink in the bathroom called a vacuum breaker check valve manufactured by B&B Valves model number 571. Once we discovered that the leak was coming from there, we looked up the model number thinking to order and replace it. We discovered quite a few complaints about the exact same problem with the valve that we were having.

The valve prevents bacteria and waste from entering the supply water. The replacement is Cash Acme Type V101 Vacuum Breaker with Check Valve
Item# V101 ordered from PDX RV LLC parts@pdxrv.com.

We ordered it but haven't received it yet. I'll update this post once we receive it and install it.

Thanks for your help.

do you have/checked washing machine hookup?

Is it raining? Are you connected to shore power or using your water pump? Are you using your air conditioner and is it located above the wet spot on the floor?