Main Heat Exchanger; Characteristics; Removal; Cleaning - Savio GAIA 424 S Service Manual

5

Main heat exchanger

5.1

Characteristics

The main heat exchanger (A in fig. 12) has the function
of transferring heat of the gas produced by combus-
tion to the water circulating in it.
A
fig. 12
The hydraulic circuit consists of five elliptic pipes con-
nected together in series (fig. 13).
fig. 13
5.2

Removal

Warning: isolate the boiler from the mains
electricity supply before removing any
covering or component.
1 Empty the main circuit of the boiler
2 Remove the front panel of the case
3 Remove the sealed chamber cover.
For models 424 S, 424 RS...
4a Remove the cover of the combustion chamber;
5a Remove the front part of the flue gas hood by un-
screwing the screw B (fig. 14a)
D
fig. 14a
For model 428 S...
4b Remove the front part of the flue gas hood by un-
screwing the four screws C (fig. 14b)
5b Remove the cover of the combustion chamber
D
fig. 14b
6 Unscrew the automatic air valve connection nut
D and remove the valve (fig. 14a);
7 Separate the heat exchanger from the hydraulic
circuit, loosening the inlet and outlet pipe fittings;
For models 424 S, 424 RS...
8a move the right pipe and free the right connection;
lower the right side of the exchanger and extract
it from the front;
For model 428 S...
8b Extract the heat exchanger, from the front;
Unscrew the pipe E (fig. 14b) from the heat ex-
9
changer;
10 Assemble the heat exchanger carrying out the re-
moval operations in reverse sequence.
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.
E B
E C
11