An electric geyser is used domestically to heat
water. It is usually cylindrical shaped and mounted on walls. It may
have a capacity of 50 to 250 liters.
It consists of a water
container vessel with an inlet for cold water and an outlet for hot
water. The heater contains a thick electric conductor coil element. It
gets heated due to the dissipation of energy when current passes through
it. The heat energy is transmitted to water through conduction and
convection mechanisms. Usually the heating element is made of Nickel or
There is a mechanism to measure the temperature of
water using a thermostat. It shuts off, automatically, the current
supply to the heating element, when the temperature is above a preset
value. This is set in the factory. There may be LEDs or small bulbs to
indicate whether the heater is switched on or off.
container is usually made of a material which does not get corroded or
rusted easily. The water container is protected with insulating
material and air gap so that the heat energy is retained inside the
container. The materials for the outer casings are usually stainless
steel, plastic and china glass. Plastic is safer to prevent from
leakages and shocks.
The heater is usually based on AC voltage.
It is given a rating : power it consumes, current it passes when the
rated voltage is applied. Voltage rating could be 220 V in countries
like India and 110 V in USa. Power rating could be 1 KW to 5 kW
depending on size.