Hot Water Cylinders

Open Vented Hot Water Cylinders

With open vented systems a large volume of cold water is stored in a header tank located more often than not in the Loft. The water storage cylinder is usually located in the airing cupboard and is fed at the base of the cylinder by the Cold Water from the header tank. The Water pressure and flow within an open vented hot water cylinder is forced through by gravity, i.e. the weight of stored 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, providing it is lower than the stored water level. With this in mind, the Higher your Header Tank, the better pressure of water you will achieve when using an open vented hot water cylinder.

When the water is heated it rises to the top of the hot water cylinder where it can be drawn off through the hot water supply pipes and tap. You can have Showers fitted to an open vented system but it is recommended you fit a separate feed for a Power/Mixer shower. This can be achieved by using a Surrey/Warwix flange, and these can be fitted onto an already fitted cylinder but for new Cylinder situations you can request for a secondary return connection be fitted. This is normally fitted towards the top of the hot water cylinder which enables you to take a feed directly to the shower as opposed to taking water from the normal supply which can cause air locks.

Heating up the water within an open vented hot water cylinder causes expansion, a vent pipe allows a safe route for excess pressure, air bubbles and steam should the system overheat, it runs from the top of the hot water cylinder back up to the cold water storage header tank where its vent pipe is located just above the water level.

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 are normally fitted into Flats as there would be no loft space to fit the Header Tank.

Direct Hot Water Cylinders

This is the simplest form of water heating, it gets its name from the fact that the water drawn from the hot taps has been directly heated via the Electric without the need of a boiler. A >Direct Hot Water Cylinder> will either use 1 or 2 Immersion Heaters (3Kw) depending on the overall size of the Cylinder. This form of water heating can actually be a very slow process compared to the Indirect and will take over an hour for you to actually achieve the optimum temperature.

Indirect Hot Water Cylinders

With an indirect hot water cylinder, the water is heated via a boiler whether it be Gas/Oil or Electric. It uses the power from the boiler to heat it through the coil inside the cylinder which also speeds up heat up times compared to the Direct hot water cylinders. Water circulating around the boiler, pipes and radiators is kept totally separate from the stored water in the cylinder that is used for bathing/washing up etc. With this setup, heating of the water is dramatically speeded up and optimum temperature can be achieved within at least 30 minutes from cold.