Shower compatibility with WWHRS
WWHRS is designed to work with Thermostatic mixer showers only. Additionally, only thermostatic mixer showers are allowed/recognized for use with WWHRS by SAP.
A thermostatic mixer will regulate/maintain the desired output temperature at the shower head while adjusting the mix between hot and cold, as the WWHRS operates. A standard electric shower is not normally able to do this.