These types of systems are the most common in UK households. it has a cold water storage tank, normally in the loft area, hot water storage cylinder and a seperate boiler, normally installed in the kitchen.
The advantages of this system are:
Hot water to several taps at the same time.
Greater volume of water, which means a bath will fill quickly
When used in conjunction with a fast recovery hot water cylinder(see further information, hot water can be available almost 24/7 and efficiently.
The disadvantages of this system are:
If you require a powerful shower, a mechanical pump will be required to increase the shower pressure.
Take up more room i.e. airing cupboard and loft
Greater Risk of freezing pipes in the loft area
This is the most typical of the systems currently fitted in the UK.
It is generally suitable for average to larger homes where hot water will be needed at more than one tap at a time such as families of three or more with perhaps more than one bathroom/shower room.
When fitted with fast recovery/high efficiency hot water cylinders this type of system will be almost as efficient as a combination boiler but will serve several taps at a time