Cozy Low-Energy Shower

Step 18 C) Temperature Stabilization: Testing and Using

If you are sure none of the joints in the valve assembly are leaking, test the hot and cold water individually at the shower. Next try mixing a moderate temperature, and turning off the flow at the shower head. Go away for a few minutes, and come back and turn the flow back on. It should start up right at the same temperature, and stay close to that temperature.

One further step you can take to help maintain a more constant temperature is to insulate the hot water pipes wherever they are accessible. That will save additional energy as well as keeping the temperature more stable.