Instruction Manual

0020107232_03 - 12/14 - Glow-worm
INSTALLATION
- 16 -
5 Water systems - Domestic Hot Water
5.4 General
All domestic hot water circuits, connections, ttings must be
in accordance with the relevant standards and water supply
regulations.
For GB: Guidance G17 to G24 and recommendation R17 to
R24 of the Water Regulations Guide (for Scotland, the Water
Byelaws 2000, Scotland).
For IE: The current edition of I.S.813 “Domestic Gas
Installations”.
5.5 Water Pressure
The minimum working pressure to obtain the maximum
domestic ow is:-
24cx 1.0bar
30cx 1.0bar
35cx 1.0bar
The maximum working pressure of the domestic hot water
circuit is 10 bar. If the cold water supply pressure exceeds this,
then a pressure-reducing valve must be tted in the supply to
the boiler.
5.6 ‘Hard’ Water Areas
The temperatures within the heat exchanger are limited by the
boiler control system to minimise scale formation within the hot
water pipework. However, in areas where the water is ‘hard’ (i.e.
more than 200mg/litre), it is recommended that the hot water
setting is reduced and that a scale reducer is tted, refer to the
manufacturer’s instructions or consult the local water company
for additional advice.
5.7 Domestic Water Flow Rate
The water ow rate is restricted to a maximum 9.4 l/min for
24cx, 11.7 l/min for 30cx and 13.0l/min for 35cx by a restrictor
factory tted within the boiler.
15725
Diagram 5.3
5 Water Systems - Sealed Central Heating
system
5.8 Flow Rate
If it is necessary to alter the ow rate, the system can be tted
with a lockable balancing valve in the main ow or return pipes
shown as valve “A” in diagram 5.3. The ow rate through the
boiler must not be allowed to fall below that given in section 1 -
Specication Table.
5.9 Bypass
The boiler is tted with an automatic bypass.
Diagram 5.2 shows the pump head remaining for the heating
system depending on the bypass setting and the speed setting
of the pump, see section 11 Commisioning.
Ensure that under no circumstances does the ow rate drop
below the gure specied, refer to section 1 - Specication
Table and section 11.9.
5.10 Safety Valve
The safety valve is an integral part of the boiler and it cannot
be adjusted. The pipe from the safety discharge valve must
not discharge above an entrance, window or any type of public
access area.