Glow-worm 12 hxi G.C.No. 41-019-01, Installation And Servicing, Page: 15 / 48

0020107233_00 - 06/11 - Glow-worm
INSTALLATION
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5 Water Systems - General
5.1 General
This boiler is designed to provide central heating from a fully
pumped open vented or sealed water system and domestic
hot water using a fully indirect vented or unvented cylinder.
An options board accessory is available to activate and link
the internal programmer with a Honeywell S or Y plan system.
Domestic Hot Water Cylinder
SINGLE FEED INDIRECT CYLINDERS ARE NOT
SUITABLE.
The domestic hot water cylinder must be of the double feed
fully indirect coil type.
Draining Points
Draining taps must be provided at all low points of the system,
which will allow the entire system to be drained.
Draining taps shall be to the current issue of BS2879.
5.2 Pump
The pump should be fitted on the flow pipe from the boiler and
have isolating valves each side.
A variable duty pump should be set to give a temperature
difference of no greater than 20
0
C between the flow and
return, with the thermostat set at “MAX”, which is about 80
0
C,
to give a flow rate as given in the table.
See chart for pressure loss of the boiler, diagram 5.1.
High resistance microbore systems may require a higher duty
pump.
5.3 flow Rate
If it is necessary to alter the flow rate, the system can be
fitted with a lockable balancing valve in the main flow or
return pipes shown as valve “A” in diagram 5.3. The flow rate
through the boiler must not be allowed to fall below that given
in diagram 5.1.
5.4 bypass
A system bypass ‘B’ will be required fitted at least 1.5 metres
away from the boiler, refer to the current issue of the central
heating system specifications (CHeSS).
5.5 Water Treatment
existing system- It is ESSENTIAL that prior to installing
the new boiler the system is thoroughly flushed.
new system- For optimum performance after installation,
the boiler and its associated central heating system should
also be flushed.
Flushing should be carried out in accordance with BS7593:
2006 using a cleanser such as Sentinel X300 or X400,
Fernox Restorer or Salamander corrosion guard cleaner.
IMPoRTanT: Ensure all cleanser is removed from the whole
system before adding an inhibitor.
For long-term corrosion protection, after flushing, an inhibitor
suitable for stainless steel exchangers should be used, refer
to the current issue of BS 5449 and BS 7593 on the use of
inhibitors in central heating systems. Examples are Sentinel
X100 Fernox Protector or Salamander corrosion guard
inhibitor.
Water Systems - Domestic Hot Water
5.6 Unvented DHW System
General - All domestic hot water circuits, connections, fittings
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) .
Document G Sanitation, hot water safety and water efficiency,
section 3 of the building regulations, requires that the
installation of an unvented system should be notified to the
local authority Building Controls Department and that the work
must be carried out by a competent person approved at the
time by the Health and Safety Executive, as defined in the
approved document G3.
for Ie : The current edition of I.S.813 “Domestic Gas
Installations”.
Where a storage system will not have a vent to atmosphere
the installation must comply with the building regulations and
the Water Supply (water fittings) regulations 1999 and water
byelaws 2000, Scotland, see also the current issue of BS5546
and BS6700.
If fitting to an existing system the local authority should be
informed.
5.7 Vented DHW System
General - All domestic hot water circuits, connections, fittings
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”.