When you do renew the PRB diaphragm, leave the triton head on and turn the temperature control to its hottest, (minimum flow) and put the power switch to its coldest setting, Off, then measure the flowrate (with triton showerhead), change the shower head to your new one and measure the flowrate again, post back.So in that case no showers then as they are all electric. The ad doesn't state that it can't be used on electric showers.