Unvented Hot Water Cylinders.

An unvented pressurized hot water cylinder is fed from mains cold water, the pressure in the mains water pressurises the cylinder to 3 Bar allowing for a high flow rate when drawn off to feed either taps or showers. The unvented cylinder can be either Direct, heated by electric immersion heaters, or Indirect, heated vis a boiler, either gas, oil or electric.

Open Vented Hot Water Cylinders

Open vented systems store a large volume of cold water in a header tank located in the Loft. The water storage cylinder is fed at the base of the cylinder by the Cold Water from the header tank. The Water pressure and water flow within an open vented hot water cylinder is forced through by gravity, the weight of water in the header tank is usually sufficient to push water down the pipe that feeds the hot water cylinder and back up to any tap or shower outlet, the cylinder should be lower than the stored water level. The Higher your Header Tank, the better the water pressure when using an open vented hot water cylinder.

Combination Hot Water Cylinders

A combination hot water cylinder has its own built in cold-water header tank fitted on top of the cylinder. They are available as direct and indirect cylinders and will be used where there is be no loft space to fit the Header Tank.

Direct Hot Water Cylinder.

The direct hot water cylinder is heated using immerrsion elements, so the water is heated directly from the element and drawn off in the usual way.

Indirect Hot water cylinders.

With an indirect hot water cylinder, the water is heated via a boiler eitherGas/Oil or Electric. It uses the power from the boiler to heat it through the coil inside the cylinder, the heat from the hot water in the coil is transferred to the cold water in the cylinder heating the water to the desired temperature.