What hot water system do I have?

Below is a nice and easy explanation of the two different types of hot water systems that can be found in most homes:

Low pressure system.
In this system you store cold water in your loft, or as high in the house as practicable. This cold water store is linked by a single pipe to the hot water cylinder below and the whole system works using gravity, when you open a hot water tap, the cold water in the storage tank runs down the connecting pipe and into the base of the hot water cylinder, pushing the hot water out of the top of the cylinder and off towards the tap. Kensington Plumbers can fit new hot water storage systems.
When you turn the cold mains tap off you stop the cold water storage tank from being refilled, the hot water itself will not stop running until the tank is empty. This tank usually holds at least 114lts of water but it can be much, much larger. It is such is not a good idea to rely on emptying the cold water storage tank every time you want to stop your hot water running.

High-pressure system.
If turning off your mains stop tap turned off your hot water as well as your cold, then your hot water is known as a high-pressure hot water system and is delivered either instantaneously or by an unvented hot water cylinder. A Kensington Plumber is able to explain the differences in systems. In both cases the hot water is powered by the cold water pressure, so when you turn off the mains stop you deprive your hot water of this pressure and as a result nothing comes out of the hot water taps.

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