H.w. Heat Exchanger; Function; Removal - Biasi Activ A 25C Service Manual

6 D.h.w. heat exchanger
6.1

Function

The d.h.w heat exchanger A in Fig. 6.1 and Fig. 6.3 al-
lows the instantaneous transfer of heat from the primary
hydraulic circuit to the water destined for d.h.w use.
Fig. 6.1
The schematic structure is shown in Fig. 6.2.
Primary hydraulic circuit
Domestic hot water circuit
Fig. 6.2
6.2

Removal

Warning: isolate the boiler from the mains
electricity supply before removing any
covering or component.
1
2
3
4
5
6
A
Fig. 6.3
7
Reassemble the d.h.w. heat exchanger carrying out the
removal operations in the reverse order.
Attention. When reassembling the exchanger be
sure to put the off centre location/securing pin indi-
cated in Fig. 6.4 towards the left side of the boiler.
Fig. 6.4
Remove the panels of the case.
Empty the primary circuit and the d.h.w circuit of
the boiler.
Remove the control panel following the instruc-
tions from 3 in section 2.3.
Remove main electronic p.c.b. box following the
instructions from 5 in section 2.4.
Remove the pump following the instructions in
section 7.3.
Completely unscrew the Allen key screws B
(Fig. 6.3) which hold the exchanger to the plastic
groups.
B
Move the exchanger towards the rear of the boiler
and extract it leftwards.
Warning: to lubricate the O-- ring gaskets
exclusively use a silicone base grease
compatible to be in contact with foods and
approved by the local water Authorities.
A
B
13