The pump can be found after the primary heat exchanger within the heating appliance and allows the heated water to be circulated within the closed heating system. In the design of most combi boilers, the pump is usually situated before the diverter valve to allow circulation through the central heating and DHW systems."
The pump is of the canned rotor type, i.e. pump and motor form an integral unit without shaft seal and with only two gaskets for sealing. The bearings are lubricatd by the pumped liquid. The pump has 3-step speed selector. The pump is characterized by:"