Biasi M275V.2024 SM, Service Manual

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CONDENSING HEAT EXCHANGER
5 CONDENSING HEAT EXCHANGER
5 .1 Function
The Condensing heat exchanger "1" in Figure 5.1 has the func-
tion of transferring heat produced from combustion of the gas
and from the flue exhausted gas to the water circulating in it.
Figure 5 .1
1
2
3
By reducing the combustion products temperature, the latent
heat of the vapour is transferred to the water circuit, allowing an
extra gain of useful heat.
The condensed vapour is then drained through the condensate
trap "3" and the draining pipe "2".
5 .2 Removal
Warning: isolate the boiler from the mains electrici-
ty supply before removing any covering or compo-
nent .
1 Disconnect the flue system from the boiler.
2 Remove the fan group (rubber pipe, gas pipe) following the
instructions from 1 to 6 in section "17.2 Removal of the Air
box and the Fan" on page 41.
3 Disconnect the detection / ignition electrode connector "4".
4 Disconnect the fan connector "5" by pressing the plastic hook
placed on the side of the connector (Figure 5.2).
5 Unscrew the nuts "6" (Figure 5.2).
6 Remove the fan-burner group "7".
7 Empty the primary circuit of the boiler.
8 Remove the clips "8" (Figure 5.2).
9 Loosen the connection "10" and slightly move the pipe "9" up-
wards, turn it towards left (Figure 5.2) and then move the pipe
downwards freeing it from the Condensing heat exchanger.
10 Loosen the connection "11" and slightly move the pipe "12"
upwards, turn it towards left (Figure 5.2) and then move the
pipe downwards freeing it from the Condensing heat ex-
changer.
Figure 5 .2
4
5
6
7
8
9
10
11
12
Figure 5 .3
13
14
11 Unscrew the screws "13" and remove the clamps (Figure
5.3).
12 Disconnect the connector "14" by pressing the plastic hook
placed on the side of the connector (Figure 5.3).
13 Remove the Condensing heat exchanger by levering it and
sliding it forwards.
14 Reassemble the Condensing heat exchanger carrying out
the removal operations in reverse order.