General requirements
rev 17 09 93
19
Expansion vessel
The appliance has an integral sealed expansion
vessel to accommodate the increase of water vol-
ume when the system is heated.
Refer to Tab. 4.1 on page 11 for its technical 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 return valve,
without the approval of the Local Water Authority.
Filling
A method for initially filling the system and replac-
ing water lost during servicing must be provided
and it must comply with local water authority regu-
lations.
The correct method is shown in Fig. 5.4.
The temporary connection must be removed
immediately after filling.
Temporary
connection
Control valve
Control valve
Double check valve
Supply pipe
(cold water inlet)
C.h. return pipe
Fig. 5.4
The installer should ensure that no leaks exist
either inside the boiler or on the system as fre-
quent filling of the system could cause premature
scaling of the heat exchanger.
5.9
Water treatment
Central heating circuit
Where a new boiler is fitted to a new system 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 de-
bris 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 sec-
tion 7.3 of this manual.
5.10
Electrical supply
Warning, this appliance must be earthed.
External wiring to the appliance must be carried
out by a competent person and be in accordance
with the current I.E.E. Regulations and any local
regulations which apply.
Reference should be made to the current ETCI
rules for electrical installations.
For Ireland (IE), refer to I.S.813.2002.
The boiler is supplied for connection to a 230 V~
50 Hz supply. The supply must be fused at 3A.
The method of connection to the electricity supply
must facilitate complete electrical isolation of the
appliance by the use of a fused spur isolation
switch. Its installation permits a complete switch-
ing off in the conditions of the overvoltage cat-
egory III. Alternatively it can be used a 3A fused
three pin plug and unswitched shuttered socket
outlet both complying with BS 1363.
The point of connection to the electricity supply
must be readily accessible and adjacent to the
appliance except were the appliance is installed in
a bathroom this must then be sited outside the
bathroom.
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