H.w. Heat Exchanger; Function - Biasi GARDA M90F.24S Service Manual

6 D.h.w. heat exchanger
6.1

Function

The d.h.w heat exchanger A in Fig. 13 allows the instan-
taneous transfer of heat from the primary hydraulic cir-
cuit to the water destined for d.h.w use.
Fig. 13
The schematic structure is shown in Fig. 14.
Primary hydraulic circuit
Domestic hot water circuit
Fig. 14
6.2
Removal
Warning: isolate the boiler from the mains
electricity supply before removing any
covering or component.
1 Remove the front and right hand side panels of
the case.
2 Empty the primary circuit and the d.h.w circuit of
the boiler.
3 Remove the motor of the three way diverter valve
(see section 8.3).
4 Completely unscrew the two Allen key screws B
A
(Fig. 15) which hold the exchanger to the brass
groups.
Fig. 15
5 Move the exchanger towards the rear of the boiler
and extract it.
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 center location/securing pin indi-
cated in Fig. 16 towards the left side of the boiler.
Fig. 16
B
11