Primary Heat Exchanger; Function; Removal; Cleaning - Biasi Riva Plus HE M296.24SM/C Service Manual

5

PRiMARy HEAT ExCHANGER

5.1 function

The primary heat exchanger A in Figure 5.1 has the function of
transferring heat produced from combustion of the gas to the
water circulating in it.
figure 5.1
The hydraulic circuit is composed of 8 elliptical pipes connected
in parallel (Figure 5.2).
figure 5.2

5.2 Removal

Warning: isolate the boiler from the mains electrici-
ty supply before removing any covering or compo-
nent.
1 Remove the case panels and the sealed chamber lid (section
"Body panels" page 5).
2 Empty the primary circuit of the boiler.
3 Remove the combustion chamber lid B by unscrewing the
screws C (Figure 5.3).
4 Remove the screws D and the plate E.
5 Remove the clip F.
6 Loosen the connection G and slightly move the pipe H up-
wards.
7 Remove the clip I and the safety thermostat J and the c.h.
temperature probe K. It is not necessary to disconnect it from
the wiring.
- 12 -
PRiMARy HEAT ExCHANGER
A
C
b
C
l
figure 5.3
8 Loosen the connection L and move the pipe M downwards
freeing it from the connection of the primary het exchanger.
9 Remove the clip N.
10 Loosen the connection O.
11 Free the pipe P from the connection of the condensing heat
exchanger; lift and rotate it towards right.
12 Remove the heat exchanger by sliding it forwards.
13 Reassemble the boiler carrying out the removal operations in
reverse order. Fit the clip I with the arrow pointing upwards as
illustrated in Figure 5.3.
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-metallic bristle brush.
In any case, avoid any actions that can damage the protective
varnish with which the exchanger has been covered.
Warning: After cleaning or replacement as detailed
above, if it deemed necessary to undertake a com-
bustion analysis, refer to the appropriate chapter
Maintenance of the installation instructions manual.
f
H
N
G P
J
i
K
M
E
d
o