Biasi M96.24SM/B Service Manual page 36

Fan and Air pressure switch
COM
"L " connection
N.C.
Fig. 69a
"H" connection
"L " connection
Fig. 69b
Check of the venturi device
n
This test must be carried out with the sealed
chamber closed
1 Remove the caps of the pressure test points lo-
cated on the top of the boiler and connect a differ-
ential pressure gauge (Fig. 70).
2 Switch on the boiler.
Fig. 70
3 Compare the value on the gauge with the follow-
ing minimum values:
80 Pa (0,8 mbar) --- M96.24SM/...
110 Pa (1,1 mbar) --- M96.28SM/...
34
N.O.
"H" connection
18.3 Removal of the Fan
Warning: isolate the boiler from the mains
electricity supply before removing any
covering or component.
1 Remove all the case panels, the sealed chamber
lid and the combustion chamber lid.
2 Disconnect the connectors D and the earth con-
nection E (Fig. 68).
3 Disconnect the pipe which connect the venturi
device to the Air pressure switch.
Unscrew the screw F and remove the bracket G
4
(Fig. 71).
D E
Fig. 71
5 Remove the Fan by sliding it towards left (se the
arrow in Fig. 71).
6 Assemble the fan carrying out the removal oper-
ations in reverse sequence.
Warning: Re-- assembling the fan ensure that the
hooks around the inlet port of the fan hung correctly
on the flue hood.
Warning: to correctly connect the venturi device to
the Air pressure switch, refer to Fig. 72.
Fig. 72
Warning: After cleaning or replacement as
detailed above, if it deemed necessary to
undertake a combustion analysis, refer to
the appropriate chapter Maintenance of the
installation instructions manual.
F G
--- +
C