Thank you! I was able to take apart the shower and noticed that the plastic piece (3.1on the diagram) was broken in the center on the hot side. It looks like there was a spring pushing a plastic stopper against the "+" grid, so basically there is now a straight hole to the cartridge. I reassembled the unit back together and everything seems to be working fine and no leaks. Is there anything detrimental if I leave it the way it is?