You need to turn the camp water off and relive the pressure by opening a faucet.
Then switch over to system water use, turn on the water pump and run a few gallons out of the tank.
This should reset the check valve.
Now turn off the pump and switch back to city, things should work normal now.
Do not turn the water pump on when using city connection.
2016 F350 6.7L LB CC Reese 28K 2014 Chaparral Lite 266sab
"Those who would give up essential Liberty, to purchase a little temporary Safety, deserve neither Liberty nor Safety." 2014 19 days camping 2015 17 days camping201620 days camping