Shower Diverter Stem Removal | Home Guides

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Replace the diverter valve stem if your shower water pressure falls and water starts dripping out the tub faucet.

The shower diverter valve in a three-handle faucet system channels mixed hot and cold water from your tub faucet to the showerhead. After extended use, however, the washer on the end of the diverter valve stem becomes worn. This reduces shower pressure by allowing some water to bypass the diverter and flow into the tub. If this happens, replace the defective part; most plumbing outlets and home centers carry replacement diverter valve stems, and if you have basic do-it-yourself skills, removing the old stem and installing a new one is fairly straightforward.

Preparation Tasks

Turn off the water supply to the tub and shower before starting work. This is straightforward, provided the bathroom is equipped with suitable shutoff valves. If not, you must isolate the main shutoff valve situated between the outside water meter and the house, by turning the valve controller all the way in a clockwise direction. Some valves are fitted with a handle, some can be turned off with an adjustable wrench and others require a water supply shutoff key or "curb" key. Open both hot and cold tub faucets after shutting off the supply to release residual water pressure in the pipes and to prevent leaks during installation. As an added precaution, cover the tub drain with a hand towel to prevent any dropped parts falling down the drain hole.

Stem Disassembly

Remove the decorative cap covering the screw securing the diverter valve handle, undo the central screw and pull the handle straight off the stem. Remove the outer housing by twisting it off in a counterclockwise direction as far as possible and then loosening the white inner nylon stem protruding through the housing with pliers before spinning the housing off. Use a long 15/16-inch tubular socket wrench to undo the stem securing nut inside the opening. Grip the tubular wrench with channel pliers and then twist counterclockwise. Once the nut is loose, spin it off the rest of the way with the tubular wrench. Wiggle the stem from side to side to loosen it and then pull it straight out. Clean any remaining debris off the valve seat inside the body with a damp rag before installing the new valve stem.

Installing New Valve

The new stem has two preinstalled white nylon washers. Slide the outer washer over the securing threads and rest it against the outside flange behind the threads. Wrap plumber's tape tightly around the threads in at least four clockwise spirals until the threads are covered. Slide the second nylon washer over the inner barrel on the stem and rest it against the second flange in front of the threads. Twist the valve stem counterclockwise to the open position to hold the washer in place, and insert the new stem into the diverter body. Tighten the stem as far as possible with the tubular wrench by hand, and then snug it down with the channel pliers without overtightening.

Water Test

Turn the water supply back on. Slide the diverter valve handle onto the stem, close the diverter valve and open the hot and cold tub faucets. Check inside the opening to ensure that there are no leaks coming from around the valve stem nut. If you notice a small drip, tighten the nut another quarter turn until the leak stops. Next, activate the diverter valve to ensure that the shower works at full pressure without water dripping through the tub spout. Once you’re satisfied, turn the faucets off, remove the handle, and replace the chromium faucet housing and handle by reversing the disassembly procedure.