Domestic Water; Water Treatment - Biasi Advance Plus 25C ERP User Manual And Installation Instructions

Expansion vessel
The appliance has an integral sealed expan-
sion vessel to accommodate the increase of
water volume when the system is heated.
Refer to Fig. 4.5 on page 25 for its techni-
cal data.
If the heating circuit has an unusually high
water content, calculate the total expansion
and add an additional sealed expansion
vessel with adequate capacity.
Mains water feed: central heating
There must be no direct connection to the
mains water supply even through a non re-
turn valve, without the approval of the Local
Water Authority.
Mains water feed: hot water supply
The domestic section of the boiler is de-
signed to withstand an internal domestic
water pressure of 10 bar. Where it is likely
that the mains domestic water pressure may
exceed 5 bar, it is possible due to internal
"water hammer" effects that the pressure
within the domestic system can increase to
a level in excess of the 10 bar limit.
In these circumstances it is therefore rec-
ommended that a 3 bar pressure reducing
valve be fitted to the incoming mains wa-
ter supply and a mini expansion vessel in-
stalled on the domestic circuit.
These devices will protect the boiler and the
domestic system from damage due to ex-
cessive domestic water pressure.
Filling
A method for initially filling the system and
replacing water lost during servicing must
be provided and it must comply with local
water authority regulations.
The correct method is shown in Fig. 5.4.
The temporary connection must be re-
moved immediately after filling.
- 42 - - 42 -
GENERAL REQUIREMENTS
Supply pipe
(cold water inlet)
C.h. return pipe
Fig. 5.4
The installer should ensure that no leaks ex-
ist either inside the boiler or on the system
as frequent filling of the system could cause
premature scaling of the heat exchanger.
5.9

Domestic water

The domestic water installation must be in
accordance with the relevant recommenda-
tions of BS 5546. Copper tubing to BS EN
1057 is recommended for water carrying
pipework and must be use for pipework car-
rying potable water.
For Ireland (IE), refer to I.S.813.2002.

5.10 Water treatment

C.h. circuit
Where a new boiler is fitted to a new sys-
tem with either plastic or copper pipes, it
is important the system is fully flushed, on
completion, to ensure flux residues, swarfs,
oils and other installation debris is removed.
Where a new boiler is fitted to an existing
system, it is important the debris from the
existing system is fully removed in order to
ensure the efficiency of the new appliance
is maintained.
Details on flushing procedure are given in
the section "Initial filling of the system" to
page 58 of this manual.
D.h.w. circuit (scale protection)
In areas where the water is 'hard' (i.e. more
than 200 ppm total hardness as defined by
Control valve
Double check valve
Temporary
connection
Control valve