Primary Heat Exchanger; Function; Removal; Cleaning - Biasi M96.24SM/B Service Manual

5

Primary heat exchanger

5.1

Function

The primary heat exchanger A in Fig. 9 has the function
of transferring heat produced from combustion of the
gas to the water circulating in it.
Fig. 9
The hydraulic circuit is composed of 8 elliptical pipes
connected in parallel (Fig. 10).
Fig. 10
5.2

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 combustion chamber lid B by un-
screwing the screws C and removing the clamp
D (Fig. 11).
Remove the screws E and the plate F.
4
5 Loosen the connection G and slightly move the
pipe H upwards.
Remove the clip I and the safety thermostat J. It
6
is not necessary to disconnect it from the wiring.
A
D
C
B
C
E
K
Fig. 11
Loosen the connection K and move the pipe L
7
downwards freeing it from the connection of the
primary het exchanger.
8 Remove the clip M
Move the pipe N upwards freeing it from the con-
9
nection and rotate towards right.
10 Remove the heat exchanger by sliding it for-
wards.
11 Reassemble the boiler carrying out the removal
operations in reverse order. Fit the clip I with the
arrow pointing upwards as illustrated in
Fig. 11.
IMPORTANT -- do not force the connection G when
tighting it.
5.3

Cleaning

If there are deposits of soot or dirt between the blades
of the heat exchanger, clean with a brush or non---me-
tallic bristle brush.
In any case, avoid any actions that can damage the pro-
tective varnish with which the exchanger has been cov-
ered.
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.
H
N
G
J
I
L
M
F
11