I had a similar problem with the water pump in my 2007 Kingsport. Yesterday the campground I was at had an overnight freeze warning, so the city was shut off. Before they secured the water, I filled my onboard tank and then disconnected the city water.
When I turned on my pump, it just ran and ran. I tried opening a water valve to purge any air from the line (tried opening all of the valve actually) and still didn't have any luck.
I found the pump (located under the lower bunk in the rear) and disconnected the outlet side while it was running. Only a small trickle of water came out.
Then I disconnected the input side (with the pump off) and had a brief period of minor flooding (nothing major). Put the input and output back on and tried the pump again. Pump just ran and ran. No water at any of the faucets.
In my frustration
, I smacked the pump a few times and suddenly I had water pressure.
Is there a proper way that I should be priming the pump? This is the first time that I have been without campground water, and the owner's manual doesn't provide a lot of information on the FW pump (other than never turn it on without water in the tank, and never use it with city water connected).
Also, I have noticed the while I really like the Kingsport 235BH that I have, the owner's manuals / documentation really suck. Is there a better source for information on the trailer systems / locations / and operation?