Pump; Function; Checks; Removal Pump - Biasi Activ A 25C Service Manual

7

Pump

7.1

Function

The pump A in Fig. 7.1 and Fig. 7.3 has the function of
making the water in the main circuit circulate through
the main condensing heat exchanger and therefore
through the c.h. system (during the c.h. function) or
through the secondary heat exchanger (during the
d.h.w. function).
Fig. 7.1
7.2

Checks

Warning: isolate the boiler from the mains
electricity supply before removing any
covering or component.
Check that the pump is not seized and that the
n
movement of the rotor is not subject to mechanical im-
pediments.
With the boiler off, remove the front panel. Remove the
air release plug of the pump and turn the rotor with a
screwdriver.
Check the electrical continuity.
n
With the boiler off, remove the front panel and discon-
nect the connector B (Fig. 7.3).
Measure the electrical resistance between the pump
supply connections.
Electrical resistance of the windings (at ambient tem-
perature) must be about 213 Ω (coil 1) and 480 Ω (coil
2) (Fig. 7.2).
Check the absence of starting defects.
n
With the boiler off remove the front case panel.
Remove the air release plug from the pump. Start the
boiler and with a screwdriver, turn the rotor in the direc-
tion of the arrow. If there is a defect in starting, the rotor
will begin to turn normally only starting it manually.
14
A
Check that the impeller is integral with the rotor.
n
With the boiler off remove the front and right hand side
case panels, lower the control panel and empty the pri-
mary circuit.
Remove the pump head by undoing the screws which
hold it to the pump body and check that the impeller is
firmly joined to the rotor.
480 Ω
Coil 2
Coil 1
Fig. 7.2
7.3

Removal pump

Warning: isolate the boiler from the mains
electricity supply before removing any
covering or component.
1 Remove the front and right hand side case pan-
els.
2 Empty the primary circuit of the boiler.
3 Disconnect the connector B (Fig. 7.3 --- Fig. 7.4)
following the indications given on the connector
box.
Disconnect the earth connector C
4
E
D
B
A
Fig. 7.3
5 Loosen the connection D,and pull up and turn to
the left the pipe E.
213 Ω
C
K
L