Types of Electric Water Heater (Plate Heater, Immersion Water Heater, Geyser)

An electric heating appliance that is used to heat up water is known as electric water heater. The electric water heater brings cold water in through the dip tube and heats this water using the heat produced by an electric heating element and the heated water taken out through outlet pipes.

Electric water heaters are classified into three types viz. −

  • Normal Plate Heater

  • Immersion Heater

  • Geyser Water Heater

Let's check each of these types of water heaters in detail.

Normal Plate Heater

The normal plate water heater is the simplest types of water heater. It consists of two round shaped plates made up of nickel. These nickel plates are separated by a gap of 2 mm with an insulator.

The normal plate water heaters are commonly used for heating a small amount of water such as water for shaving, dressing, etc.

Though this type of water heaters is simple in construction and cheaper, but following precautions should be made while using the normal plate heaters −

  • When the normal plate water heater is connected to supply, then do not try to immerse your finger in the water to check the temperature of water, otherwise you may get an electric shock.

  • The normal plate water heaters are very dangerous. Thus, while using the normal plate heater, the user should always ensure that the heater does not come in contact with any metallic substance.

Immersion Water Heater

The type of electric water heater which is immerged in water for heating the water is known as immersion water heater.

The body of the immersion water heater is made in the form of a U-tube or coil-shaped tube. This tube is made of stainless steel alloy or copper. The tube contains a heating element which is normally made of fine Nichrome alloy wire. The metallic tube of the immersion water heater is insulated usually by Magnesium Oxide powder. Both the ends of the tube are sealed and the supply connection is given through a three-pin plug.

In practice, the immersion water heaters come 250 W to 2 kW of power rating.

Faults Occur in Immersion Water Heater

There are various types of faults occur in the immersion water heater, some common faults and their causes are given here −

  • The rod of immersion water heater does not get heated. This fault is mainly due to broken fuse, damaged heating element, broken connection wire, etc.

  • The rod of the heater does not get heated but gives electric shock. It may be due to disconnection of earth wire or due to electric leakage (because of weak insulation) in immersion rod.

  • The heating element of the heater gets burn. This fault may be due to flow of heavy current or due to short-circuit between the element and the metallic body.

Precautions While Using Immersion Water Heater

While using the immersion type water heater, the following precautions should be made −

  • Supply should not be turned on without immersing the water heater into the water.

  • The immersion water heater should be completely isolated from the supply before removing it from the water.

  • No one should touch the immersion rod and the water filled bucket while the supply is ON.

  • Other than water, no liquid substance should be heated with the immersion water heater.

Geyser Water Heater

A water heating appliance that utilizes electric current to heat the water and a large tank to store the hot water for long duration is known as geyser water heater.

An electric geyser water heater consists of an electric heating element made of Nichrome, which heats up the water stored in the storage tank. In the geyser heater, the cold water enters the tank through the inlet valve and is heated inside the tank. The hot water be taken out from the water outlet of the geyser heater.

The geyser water heaters are usually used for heating a large amount of water, like 20 L to 70 L. To control the flow of water, a valve is installed in the pipeline and to control the temperature of the water a thermostat switch is provided which gets automatically turned OFF when desired temperature of the water is reached. The entire body of the geyser heater is electrically insulated. Also, in order to reduce the corrosion of metal body, an anode rod made of aluminum or magnesium is screwed in the water storage tank.