Gray water drains when pump on in dry camp mode?

Sprocket

I am boondocking in my tab 320S.  Before I left home, I filled the water tank in tank fill mode.  I switched to dry camp mode after I set up the camper.  I forgot to close the low point gray water drains.   When I turn on the water pump, water comes out of the low point gray water drains.  Is this normal?  Why would water go to the gray water tank before I open a faucet?

Sharon_is_SAM

There is a low point drain for hot and cold water, then there is the gray tank valve and drain.  Which did you leave open?  It sounds like you left the cold water low point drain open.  In the diagram, follow the water flow from the water tank and you will see how it funnels to the cold water low point drain.  That is fresh water, not gray water.

mgreen2

You also have a fresh water tank drain on the passenger side, behind the tire

Denny16

Additionally, it is very unlikely you had gray water leak from the fresh water system into the tank without a water faucet open somewhere, galley sink or washroom.  As shown above I. Sharon’s diagram, there is not a direct connection between the fresh water system and gray tank, except via the sink and shower drains.

Was your washroom tap open and you didn’t realize it?  Of it is possible some water was present in the tank, not completely drained, and the vibration from the water pump caused it to drain out.

Taking Sharon’s response into consideration, you need to do some more tests, and find exactly where this water is leaking out from.  Your gray water drain, is forward of the Nautilus and low point drains, under the trailer next to its pull out handle.
 Cheers 

Sprocket

What a great diagrams.  Yes, I left the low point drains for hot and cold water open. Drivers side

Denny16

Issue sorted!
Cheers