| 摘要 |
<p>The water circuit (10) for a combined service wall-mounted gas-fired boiler includes a primary circuit (11) in which the hot water for room heating is circulated and a secondary circuit (12) in which hot water for domestic use is circulated. In order to fill with water the primary circuit (11) of the boiler and the room heating units connected thereto through pipes (M,R) a three-way valve (32) is provided. This valve (32) is arranged so as to connect the primary circuit (11) or the secondary circuit (12) to the water mains (D) or to disconnect both therefrom. When the filling with water of the primary circuit (11) and the room heating units is required, the three-way valve (32) connects the primary circuit (11) to the water mains (D), while during the normal operation of the boiler the three-way valve (32) connects the secondary circuit (12) to the water mains (D). <IMAGE></p> |
