Removed by OP

[ba5online]

Removed by OP

 

[danemayer]

Judging from the picture, it doesn't appear the valves are a bypass, but rather just let you shut off the water while changing the filter.

I'd suggest you remove the filter before pumping in antifreeze. After you de-winterize, put in a new filter.

 

[ba5online]

Closing these valves will cut off water to the entire RV.
I found out when trying to blow air into the lines with Anderson valve set to "City" and I had these valves closed.