An immersion heater is another name for an electrical element that is fitted in a large volume cylinder of water in order to heat the water. It is a very old but tried and tested way of supplying heated water for domestic use.
An electrical element heats the water in the tank, which is controlled by a thermostat that supplies current to the element if the temperature of the water in the tank should fall below 60°C. This will give the user some protection from scalding (a maintained level of temperature). Southwark Plumbers can fit immersion heaters to cylinders.


The cold water is fed into the cylinder from the bottom. The immersion heater or maybe heaters (as more can be fitted), begin to induce heat into the water. When heated, this water is drawn from the top of the tank. Should the heater be fitted in an unvented cylinder it must be fitted with a high limit cut-out thermostat which is set at (90degrees C) so that the water will not carry on heating until it boils. There is a the possibility that something called legionella might develop in these kind of heaters. This is a great threat to human health and safety. A Southwark Plumber is highly aware of the dangers of legionella. Legionella is not widely discussed as it is still quite rare, however the danger still exists.


NOTE:

Legionella bacteria has the potential to form in water at a temperature below 60° centigrade, however it does not survive for long at this temperature and perishes if the temperature rises. It can survive between 20°C and 40°C and will usually spread itself in the form of a vapour or a mist. Providing the water temperature is regulated there will not be an issue with the legionella bacteria.