Electric Water Heater

The heater which is used for heating water is called water heater. It is of three (3) types i.e.

1. Normal Plate Heater,
2. Immersion Heater,
3. Geyser Heater.

Normal Plate Heater

It is used for heating small amount of water, like water for shaving. Its construction is very simple, consisting of two numbers of round nickel plate joint together duly separated by insulator in between them. The outer surface is insulated by plastic round plate. Both the round nickel plate is set with a gap of 2 mm with the help of insulator.

Precautions about Normal Plate Heater

1. This type of heater is very dangerous. While using this heater one should always keep on watching that it does not come into contact with any metallic substance.
2. Do never try to immerse your finger in the water to check the warmness of the water.

Immersion Heater

The heater which, immersed in water for heating the water is called Immersion Heater. In market from 250 watt to 2.0 kilo watt immersion heaters are available. The body is made of metallic substance, and the heating element is made of copper which is installed inside the capillary tube. The tube is found in ‘U’ or Coil shape. The capillary tube is filled with magnesium oxide which works as insulator. Both the end of the tube is sealed. The supply connection is given through 3 pin socket and plug.

Fault and its Causes of Immersion Heater

Fault	Cause
1. The rod of Immersion heater does not get heated.	1. The fuse, element or conductor of the immersion heater is disconnect or dislocated. 2. There may be non supply of A.C. in the socket.
2. The rod of Immersion heater does not get heated but gives shock.	1. Due to leakage in immersion rod. 2. Due to disconnection of natural or earth line.
3. The heating element of the immersion rod gets frequently burn.	1. Excessive flow of current. 2. The wire or mica may be broken and touched with the metallic body.

Precautions about Immersion Heater

1. Without immersing the water heater in water, supply cannot be given.
2. One should not touch the immersion rod when supply is ON.
3. Before switching Off the immersion rod heater should be disconnect from the plug socket.
4. Never use broken plug and also see that it is not loose.
5. Don’t touch the bucket while the supply is ON, of the immersion heater.
6. While checking the immersion heater, stand in dry wooden plank or rubber.
7. Except water no other liquid substance should be heated by immersion heater.

Geyser Heater

The basic principle water geyser is not very complex one. It is simple. Here electric heating element is used to heat up the water stored in a storage tank. The only difference from normal immersion type water heater, that it can automatically control the temperature the water by controlling the operating period of the heating elements associated with the geyser which cannot be possible in normal immersion type water heater.
Geyser heater is used for large quantity of water. Generally, from 20 ltr to 90 ltr capacity geyser is found in the market. In the storage tank one or two heaters are fixed. For supplying of cold or hot water, specific pipe lines are fitted with the storage tank. That means inlet cold water and outlet hot water pipe. To control the flow of water, valve is installed in the pipe line. To control the heat one thermostat switch is there. The switch gets automatically OFF to avoid misuse of heat. The entire body of the geyser is insulted. When the cold water flows through the valve of the geyser and there after when it is filled up, the water flow through over flow pipe, in this condition the valve gets automatically Off. An anode rod made of aluminum or magnesium is screwed in the storage tank to reduce corrosion of metal body and metal parts of the water storage and supply system. This is because the metal of anode rod is more sensitive to corrosive reactions than the metal of the body structure of the system. Body of the storage tank is generally made of steel. As the metal of anode rod i.e. aluminum or magnesium is corroded and makes the water soften before it can corrode the steel.