The diagram below shows how a central heating system in a house works. Summarize the information by selecting and reporting the main features, and make comparisons where relevant. You should write at least 150 words.

The diagram shows how a central heating system in an ordinary house works to provide not only hot water but also heating throughout the house.

The first stage is the introduction of cold water. This is done through the ceiling of the house and stored in a water tank in the upper section of the house. Attached to this storage tank is a pipe which leads to the boiler – where the water is heated – and a pipe which leads to the taps which provide hot water. Pipes also pass through the storage tank which allow for the recycling of water, and pipes to a water tank in the ceiling to allow for easy gravity feed to refill the storage tank. Excess water is fed through an overflow pipe which is either used as cold water throughout the house or is fed back to the storage tank

To provide for the heating of the water for general use and to heat the house, a boiler is located below the storage tank again to allow for gravity feed. Water passes through the boiler, is heated up and then flows to the hot water radiators placed around the house. As the water cools in the radiators it is forced into the recycling pipes and fed back to the boiler. To allow for the upward movement of water, a pump is employed. Task achievement Coherence and Lexical resource Grammatical range cohesion and accuracy FAIR Very Good Very Good Very Good

• attempts to address • arranges • uses an adequate • uses a mix of simple the task but does not information and ideas range of vocabulary for and complex sentence cover all key features coherently and there is the task forms a clear overall progression • attempts to use less • makes some errors common vocabulary in grammar and • may confuse key • uses cohesive but with some punctuation but they features with detail; devices effectively, but inaccuracy rarely reduce parts may be unclear, cohesion within and/or communication irrelevant, repetitive between sentences • makes some errors or inaccurate may be faulty or in spelling and/or word mechanical formation, but they do not impede • may not always use communication referencing clearly or appropriately