There are two basic types of electric hot water heaters used in domestic kitchens, the immersion type and the instantaneous type.
The immersion type of water heater utilises a heating element in the base of the water tank. A thermostat switches on the electrical supply to the element which gets hot, heating the surrounding water. Once the water in the tank is at the desired temperature, the thermostat switches off the supply of electricity to the immersion element. This is similar in operation to the electric kettle. The instantaneous water heater operates in a way more akin to the electric shower. These supply hot water on an instantaneous and continuous basis by passing water directly over the electrodes which boil the water immediately.
Both types allow the flow of water to the user via a tap or faucet. Drawn off water is immediately replaced via a cold water feed pipe.
