There are two types of electric water heaters:

(A) Immersion Heater:

It is im­mersed in water. It is cheap and portable. It is made of a chromed iron or brass pipe in which a heating element is placed. Around the element there is insulation so that it may not touch the pipe. Full rod has to be replaced when found defective.

(B) Self-contained Water Heater:


It consists of a storage vessel heavily gigged only at one, electrically heated and provided with a thermostat. The self-contained heater can further be divided into two types:

(a) None pressure type water heater:

Shows non-pressure type heater. When the hot water is required only at one service point, this type is used. It generally has as open outline i.e., without a stop cock on the outlet side. It essentially consists of a cylindrical heating element chamber and a thermostat.

(b) Pressure Type Water Heater:


This type of water heater is also some- times flies called Cistern type heater. When the hot water is required at more than one Points and only one heater is to be used, this type is used.

This type of heater gets its cold water supply through a cistern which is connected to the water main and supply to it is controlled with the help of a float valve as shown in Fig. 4.43 Efferent types of water heaters suggested for different places :-

Kitchen- 1.5, 3 or 5 gallon pressure type heater.

Bath room – 12 gallon non-pressure type heater.


Small family where whole day water is required.

12 gallon pressure type heater.