Myth: Leaving a water tank on continuously will save energy because the water will not have to be heated from cold each time it is switched on.
Reality: Smaller water heaters and hot drinks machines should be left on during busy periods. However, they should be switched off when not in use and after hours to save energy and money.
Change the settings of your water heater to its lowest setting, or completely off, when you leave for work or at night. As long as the tank has a good insulating jacket, it will keep the water hot all day, without needing to be constantly reheated. You can use a timer to heat your water for an hour or two each day just before you would usually need hot water for baths or showers. Modern washing machines, dishwashers and electric showers take cold water and heat it themselves so you don’t need a supply of hot water waiting for them in the tank.