Your check valve is stuck open. It can be caused by the check valve not seating properly, construction debris in the lines or running your water pump while having the city water on.
1) Turn off the city water.
2) Open a faucet to relieve pressure.
3) Turn on your water pump for a minute or two.
4) Repeat step 3.
5) Shut off faucet, let water pump run until it stops.
6) Shut off water pump.
7) Turn on city water.
8) Drain fresh water tank, not necessary if you mind carrying the extra weight.
You might have to clean the faucet aerator/screen if it is caused by construction debris.
Richard & Jill
2014 Flagstaff 832IKBS Classic Super Lite
2018 Silverado 1500 Crew Cab Z71 4WD All Star Edition
Camping since 1989
Car Shredder Op/Tech, Scrap Metal Recycling - retired
I deserve hazard pay when camping with my relatives.