the cold water faucet in Yuma, AZ from June 1st to Oct 1st....we turn off the water heater and do dishes and shower just by turning on the cold water.....now the heater may be off,,,but water still flows in and out of the tank....so if we want a comfortable shower, we have 1 mintue of cool water in the tank from over night cooling after that mintue, the hot ground water enters the tank.