Immersion heaters are heaters in which the heating elements come in direct contact with the medium. Immersion heaters are used to heat water and other non-flammable liquids which are held in containers made of stainless steel or glass.
Since, the heat generated in the elements is directly passed on to the medium, the efficiency of immersion heaters is almost 100%. Immersion heaters usually come with a thermostat which is usually mounted above the elements in an insulated box.
Immersion heaters used for heating corrosive media are designed with special corrosion resistant materials. Immersion heaters come in a range of piping options such as welded, flanged and threaded.
When used with water or any other conductive material, care should be taken to earth the vessel and the heater body as there may be a risk of electric shock in case of current leakage within the elements.