Easiest thing to do would be to get rid of the bypass valves or don't let them bypass.

No idea if it would hurt the valves or not but it might be possible to just plug the hole on the valves that goes to the tank return.



After you mentioned setting it to "bypass" I was kind of thinking that that setting refers to how the flow control is plumbed, not the section valves.   

But then you said that it worked so then I wasn't sure.