Primary Heat Exchanger; Function; Removal; Cleaning - Biasi Riva Plus HE M296.24SR/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 electricity
supply before removing any covering or component .
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. It is not neces-
sary to disconnect it from the wiring.
Primary heat exchanger
a
c
b
c
l
figure 5 .3
8 Loosen the connection K and move the pipe L downwards
freeing it from the connection of the primary heat exchanger.
9 Remove the clip M.
10 Loosen the connection N.
11 Free the pipe O 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
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