Had the same problem....here's a post from another thread regarding this issue. Still haven't fixed mine....just use a cap on the CWI when using the pump.
Join Date: May 2012
Location: Southern Ontario, Canada
Originally Posted by LiftedAWDAstro
This is easily repaired by removing the whole city water connection from the camper and pulling the center pin out from the back. There will be a small o-ring in there that needs to be reseated. If you have room to work, you can pull the water line off the back and fix it on the camper.
Thanks for the repair info. I'll try that next year. This year I just screwed in a hose plug/cap when I needed to use the pump and all worked well. We're normally hooked up to city water.
2012 Eagle Lite 298RLDS
On Permanent site at Gillies Lake, Bruce Peninsula