Here is a handy how-to guide to help you replace the diverter valve in a three-handle shower faucet system. Step 1 – Cut Off the Water. Step 2 – Drain Water in Lines. Step 3 – Cover the Drain. Step 4 – Remove Cartridge. Step 5 – Remove Diverter Stem. Step 6 – Install New Diverter Stem. Step 7 – Replace the Cartridge. Click to see full answer. Similarly, how do you fix a shower diverter? Diverter Valve on a Three-Valve Shower Loosen the screw on the handle. Unscrew and remove the handle. Remove the sleeve over the diverter. Remove the diverter using a socket wrench. Unscrew the set screw. Unscrew spigot from the wall. Furthermore, what does a diverter valve look like? Here is what a diverter valve looks like (Worcester Bosch). The diverter valve on a combi boiler works much like a lock on a canal would. It opens and closes to allow heat up both hot water and the water in the heating system which provides heat to radiators and towel rails. Accordingly, how do you adjust a shower diverter valve? You can easily adjust this yourself in a few minutes. Turn off the water supply to the washroom. Look beside, underneath or on the bathtub spout for the diverter’s holding screw. Grasp the spout and pull it straight out. Unscrew the bolt holding the diverter to the small pipe in the wall. Where is the diverter valve?It’s usually a lever that’s situated behind the bath taps that you can pull up or push down. System and conventional boilers don’t require a diverter valve. This is because the hot water they produce is stored in a hot water cylinder.