Lots of properties get their hot water from an immersion heater. The heater operates by placing a heating element or elements inside a storage vessel like a cylinder, which is full of water. The element will heat the water and then keep it at a controlled temperature. Woolwich Plumbers can fit immersion heaters to cylinders.

This electrical element is controlled using a thermostat that will switch it ‘on and ‘off should water temperature in the cylinder drop below 60°C. This temperature is designed to help stop the water from scalding. There is a cold water supply at the bottom of the cylinder that is controlled by a filling inlet valve. The heater can be made up of more than one heating element, depending on the size of the property and hot water demand. As soon as the water is at the correct temperature it is drawn from the top of the tank. If this heater is fitted in an unvented cylinder it requires a high limit thermostat which is set at 90°C so the water will not boil. There is a risk that something called legionella may form in this type of water heater. This is a great threat to human health. The legionella bacteria can form in water at a temperature below 60° centigrade, but will not survive for long at this temperature and dies if the temperature rises. Legionella survives at temperatures of between 20°C and 40°C and spreads itself in the form of a mist. As long as the water temperature is regulated it will not appear. A Woolwich Plumber is highly aware of the dangers of legionella.

The control and prevention of the bacteria will come from treating the source, which is a dirty water system. A good design and regular maintenance will stop the bacteria from forming.