Shower Valves, Arms and Trim Parts

Volume control is not a mixing valve

A volume control valve opens and closes flow, and it does not blend hot and cold water. It sits downstream of a mixing valve, or on a single supply for a hand shower or body spray, so it suits multi-outlet showers and not a basic one-handle shower. If you want to set temperature as well as flow, you need a mixing or thermostatic valve instead. Check the connection size too: half-inch threads are common, but the listing should state it.

Three parts that have to match: valve, trim, handle

A complete shower is built from the rough valve inside the wall, the trim on the surface and the arm that carries the head. Handle styles are tied to a trim series, so a lever or cross handle from another collection may not fit the stem. Look at the finish named in the title, since a model is usually sold in several finishes. Confirm the valve's depth range suits your wall thickness, so the trim plate sits flush against the finished tile.

Questions about Shower Valves, Arms and Trim Parts

Do I need to turn off the water to change a shower handle?

Not always. Swapping only the handle and trim usually needs no shutoff, but removing a cartridge or valve body does, so close the main or the local stop first. If you are unsure, shut off the supply before taking anything apart.

How long is a standard shower arm?

Most are about 6 inches long, with 12 to 18 inch extensions available. The arm threads into a half-inch fitting in the wall and the flange covers the hole. A longer or curved arm moves the head farther into the stall.

Why use plumber's tape on shower threads?

Wrapping the thread on a shower arm helps seal the connection and makes the head easier to remove later. Wind it a few turns in the direction the fitting tightens, then hand-tighten the head without a wrench that could mark the finish.