A CONTROLLABLE WATER HEATER

摘要

The invention provides an electrical water heater (220) connectable to an electrical power supply, the heater including a controller (224) controlling a switch to operate the heating element (222) located in the water heater, and the switch controller (224) being controllable to make power available to the element during selected tariff periods. The controller can be connected upstream of the switch to maintain power to the controller while the element is switched off.