Condensing Heat Exchanger; Function - Biasi M96.24SM/B Service Manual

6

Condensing heat exchanger

6.1

Function

The return water flows through the condensing heat ex-
changer A in Fig. 12 and Fig. 13.
By reducing the combustion products temperature, the
latent heat of the vapour is transferred to the water cir-
cuit, allowing an extra gain of useful heat.
The condensed vapour is then drained through the
condensate trap B and the draining pipe C.
A
B
C
Fig. 12
6.2 Removal
Warning: isolate the boiler from the mains
electricity supply before removing any
covering or component.
1 Remove the case panels and the sealed chamber
lid (see section 2).
2 Empty the primary circuit of the boiler.
3 Remove the fan D in Fig. 13 (see section 18.3)
and the air pressure switch E (see section 18.5).
4 Remove the flue thermostat F (see section 21.3)
Completely loosen the connection G and slightly
5
move the pipe H upwards.
6 Remove the clip I and move the pipe J down-
wards freeing it from the connection, then turn it
towards right.
12
Using pliers, remove the spring K moving it down-
7
wards and disconnect the rubber pipe L.
8 Remove the bracket M by unscrewing the screws
that hold it on the frame.
9 Rotate the exchanger as indicated by the arrow
and remove it towards the front of the boiler.
10 Remove the clip N and the pipe H.
F
E
D
N
H
Fig. 13
11 Reassemble the exchanger carrying out the re-
moval operations in reverse order.
After reassembling ensure that the fan-- exchanger
and exchanger-- elbow gaskets are correctly
mounted and ensure a good sealing.
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.
A
M
D I
J
K
L
G