The provided diagram depicts the process involved in a domestic central heating system.
Overall, it can be seen that there are several stages in the central heating system, starting with the collection of water in tanks and ending with the distribution of hot water in various rooms of the house.
According to the illustration, initially, water is collected in a water tank and then flows into the storage tank through an overflow pipe. Then, water passes through the boiler where it is boiled using gas or oil. After this, hot water moves to various radiators across the house. Radiators consist of small tubes to warm rooms. Finally, cold water from these radiators flows back to the storage tank using a pump that fetches water from pipelines. This whole system works in a cycle where this cold water flows again and again into the boiler and pump. Some amount of hot water is transferred to taps via the overflow pipe.