I have a recent install of a Kohler K-304 pressure balancing valve with a tub spout diverter. I had a plumber rough in the new valve. I recently installed the trim kit and discovered that water runs through the shower any time the water is turned on even when the tub diverter is not engaged. I come to find the plumber installed the valve upside down (top-down). This question may be a long shot but- is there any way to correct the problem without opening up the wall and installing the valve correctly (top-up)?? Many thanks for your help.