| 摘要 |
The pumping unit (A) is intended for a boiler (B) comprising a primary heat exchanger (21) for heating a flow of water for use in a heating circuit (22, 24), a secondary heat exchanger (25) for transferring heat from a flow of water coming from the primary heat exchanger (21) to a flow of domestic water, and a by-pass conduit (31) for protecting the primary heat exchanger (21). The pumping unit (A) comprises a body (1) with an outlet (3) and a first inlet (2), for connection to the primary heat exchanger (21) and to a return pipe of the heating circuit (22, 24), respectively, and with a second inlet (4) intended to receive a flow of heating water from the secondary heat exchanger (25). A circulation pump (7) and a three-way solenoid valve (8), in series with one another, are provided between the outlet (3) and the first inlet (2) in the body (1), the valve being further connected to the second inlet (4). The by -pass conduit (31) is formed inside the body (1). |
