Trim versus valve
The handle you see is trim. The part that does the work is a valve inside the wall, and it decides what a new faucet really costs.
- Trim
- The handle, the plate and the spout. Trim changes from the front, as long as the new trim matches the valve behind it.
- Valve
- The body inside the wall that mixes hot and cold. Makers only stand behind their own trim on their own valves, and Moen says even its own trim kits are not interchangeable across its valve types. Changing brands usually means a new valve, which means opening the wall or reaching it from behind.
- Why Delta is our default
- Delta says its MultiChoice universal valve lets you change the style and function of a shower without altering the plumbing behind the wall, and any of its 13, 14, 17 or 17T series trim fits it. Cartridges are sold as separate parts. The next repair becomes a part, not a tile job.
- Pressure-balancing or thermostatic
- Code requires one or the other on every shower, with a stop that limits the water to 120°F. Pressure-balancing reacts to a drop in pressure, like a flushed toilet. Thermostatic holds the temperature you set. Old two-handle valves often have neither.
- Low-flow heads and old valves
- Federal law caps showerheads at 2.5 gallons per minute, and WaterSense models use 2.0 or less. A valve not rated for the lower flow may not react fast enough to stop a temperature spike, so a new head can mean checking the valve too.