Hot Water Cylinders.

A hot water cylinder (also called a hot water tank) is usually found in a cupboard
(traditionally an airing cupboard) with other heating controls.
A hot water cylinder stores hot water to be used for cleaning and bathing.

Most hot water cylinders are vented and provide hot water at low pressure.
Some modern hot water cylinders are unvented and store hot water at mains pressure.
A hot water cylinder can be direct or indirect, heated by an immersion heater or a boiler.

The age of a hot water cylinder is indicated by the colour of the insulation.
A new or recent cylinder has factory fitted foam insulation which is blue or green.
Older cylinders are orange or have no insulation around bare copper.
If your cylinder has no insulation you can get a jacket to fit around it.

If a hot water cylinder is leaking it may need to be replaced. It is not usually
necessary to replace the whole cylinder if only the immersion heater needs replacing.