| 摘要 |
The central heating system comprises a first heater (100), a number of radiators (110), a first boiler (200), a radiator pump (120), a second heater (300), a circulation pump (310), a first control unit (330) and a second boiler (210). The first boiler is used to supply hot water to the radiators, and also to supply hot tap water on demand, whilst the second boiler can be called upon to work the first boiler and is connected to the central heating system via a four-way valve (400) operated by a second control unit (410). During periods when low heating is required the second heater is used only to heat water being circulated through the radiators, and with increasing heating demand more water will be fed into the second heater from the circulating radiator water. |
