Tub-Shower Diverter Valve Keeps Pressure Up

Question: The water pressure in our tub is good. However, when we turn on the shower, some water continues to come out of the tub faucet, and the water pressure from the shower is reduced. How can we correct this problem?

Answer: The problem is with the tub-shower diverter valve. When the valve is functioning properly, all the water should be channeled to the tub or shower.

There are two common types of diverters. In the tub spout diverter, a small gate valve is attached to the base of a plunger shaft located in the spout. It is held in the up position for the shower by water pressure. When the water is turned off, the gate drops and opens the tub spout. To remove it for repair, unscrew the tub spout from the threaded water pipe.

The other diverter works by rotating the valve stem so the parts in the valve body open to either the tub spout or the shower pipe. You can remove the mechanism by unscrewing the stem nut and withdrawing the diverter assembly.

Tub diverter spouts and diverter assemblies cost $10 to $15 at plumbing supply stores.

Because there are different types and sizes of tub-shower diverters available, take the old one with you to make sure you get an equivalent replacement.

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