雅思写作：Task1流程图考官范文（5）

The diagram below shows how a central heating system in a house works.

Summarise the information by selecting and reporting the main features, and make comparisons where relevant.

Sample Answer:

The given diagram shows how a central heating system of a house works. As is observed from the illustration, the central heating machine comprises several mechanical aspects and forms a complex system.

According to the given illustration, for the central heating machine to work the cold water supply is required and this water flows to the storage tank and the overflow pipe is there to store the excess water in storage. The water is passed through a boiler which is either gas or oil driven and a pump is connected with it. The radiators are connected with the boiler and these radiators are made of *all tubes. When the cold water passes through the pump and boiler, it gains temperatures and become hot water and from the water taps the house members get hot water. Thus the whole system that covers the house keeps it warm.

In summary, the central heating symtem mainly works by flowing water through the house and increasing the temperature of it.