Originally Posted by Brij
How do I get rid of gunk?
I have not seen the valve yet , nothing on exterior, going to check near the city water connection as someone suggested in this post that it might be behind some panel.
These campers don't have factory valves. (they are too cheap.) They rely instead on the check valve that is integral to the water pump to prevent city water from flowing into the FW tanks.
There is likely a clear screen fitting attached to the water pump. You most likely sucked up a single grain of dirt or other debris that clogged the check valve, and is preventing the valve to fully seal. You'd get what you are describing... eventually the FW tank will overflow.
Have you tried just running off the FW tank for a while? that flow may eventually dislodge the check valve.