Fan And Air Box; Function; Removal Of The Fan And The Air Box - Biasi Activ A 25C Service Manual

17

Fan and Air box

17.1

Function

The function of the Fan A (Fig. 17.1) is to force the mix-
ture of air and gas into the burner.
The function of the Air box B is to mix the gas and the
air in the right proportion.
The flow rate of the air---gas mixture and consequently
the input power of the boiler is proportional to the speed
of the fan that is controlled by the electronic control
p.c.b.
A
Fig. 17.1
17.2

Removal of the Fan and the Air box

Warning: isolate the boiler from the mains
electricity supply before removing any
covering or component.
1 Turn off the gas supply.
2 Remove all the case panels (see section 2).
H
A
F
D
G
E
Fig. 17.2
3 Disconnect the air manifold from pipe C by open-
ing the strip (Fig. 17.2).
38
B
Fan gasket
4 Disconnect the rubber pipe D .
Unscrew the gas connector E
5
6 Remove the fixing fork F and remove the gas pipe
G.
Disconnect the connector H
7
8 Disconnect the fan connector I by pressing the
plastic hook placed on the side of the connector.
Unscrew the screws J.
9
10 Remove the fan A with the air box B.
11 Remove the screws K and the air box B
(Fig. 17.3).
Fig. 17.3
12 Open the strip L by sliding the edges with the help
of a screwdriver and remove the Air box
Fig. 17.4.
Fig. 17.4
13 Assemble the Fan and the Air box carrying out
the removal operations in reverse sequence.
I
Before reassembling ensure the fan gasket
(Fig. 17.2) is correctly mounted.
J
Warning: Be careful not to damage the OR
gasket of the gas pipe when inserting the
pipe in the air box (air/gas mixer).
After any service operation on the components of
C
the gas circuit check all the connections for gas
leaks.
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.
K
L
K
B
K
B