Originally Posted by I-RV
Phil, be careful in selecting a shower control. Many of them are single function, where there is only cold/hot mixing and full flow. You want one with two functions; mixing and flow control.
I bought, but have not yet installed, the Delta Lahara shower valve T17238 in brushed stainless steel, that is cited elsewhere in this thread or threads linked from here. After carefully examining the documentation and reviews, I concluded that it is actually a thermostatically controlled valve, rather than merely a pressure balanced valve. Thus, it mixes hot and cold to maintain a specific temperature, which is what we really need, since our cold water temperature will vary with location and the hot water temperature will vary as the Girard or Atwood on-demand heater comes on and off.
The other type of valve is not so good, and it is often called a pressure-balanced valve. It mixes to maintain cold-hot pressure balance, which is a common problem in homes when someone flushes a toilet. Our RV problems are not with pressure balance, but in maintaining a consistent temperature.
I've got a couple of thermostatic shower heads (other brands) installed in my house and they work well.
Another advantage of this Lahara model is that the shower head has holes at the back, where air is presumably sucked into the water flow. It should give the feeling of more water volume, with low flow.
It's still winter, so I haven't installed or tested this, but I did careful research into this.
Delta Lahara 1-Handle Shower Only Faucet Trim Kit in Stainless (Valve Not Included)-T17238-SS - The Home Depot