Originally Posted by aubtig1979
Just bought a 2015 Jayco GreyHawk, 1st trip, left home with a full tank fresh water. Next AM, had very little water, I know we used hardly and water. Use city fill to fill the tank then moved to City fill and was full, Any advice...Could not see any sigh of. Any one had this problem....
This seems to be a fairly common issue. My 2015 27RLS trailer does this.
Here is a link to a thread with lots of good info.
Assuming you are sure that water has drained out, as opposed to just looking at the gauges. Then I would first verify that nothing is leaking. Then I would suspect the siphoning issue in the thread I listed. In my case I just put in the shutoff valves and travel with them closed. When I am filling and/or get to my site I open them.