8
3A.4
FLUE SYSTEM
The terminal should be located where the disper-
sal of combustion products is not impeded and
with due regard for the damage and discoloration
that may occur to building products located nearby.
The terminal must not be located in a place where
it is likely to cause a nuisance (see I.S. 813). In
cold and/or humid weather, water vapour will
condense on leaving the terminal; the effect of
such pluming must be considered. If installed less
than 2m above a pavement or platform to which
people have access (including balconies or flat
roofs) the terminal must be protected by a guard of
durable material. The guard must be fitted centrally
over the terminal. Refer to I.S. 813, when the
terminal is 0.5 metres (or less) below plastic gutter-
ing or 1 metre (or less) below painted eaves.
3A.5
AIR SUPPLY
The following notes are intended for general guid-
ance only. This appliance is a room-sealed, fan-
flued boiler, consequently it does not require a
permanent air vent for combustion air supply. When
installed in a cupboard or compartment, ventilation
for cooling purposes is also not required.
3A.6
WATER CIRCULATION
Specific recommendations are given in I.S. 813.
The following notes are for general guidance only.
3A.6.1 PIPEWORK
It is recommended that copper tubing be used in
conjunction with soldered capillary joints.
Where possible pipes should have a gradient to
ensure air is carried naturally to air release points
and that water flows naturally to drain cocks.
Except where providing useful heat, pipes should
be insulated to avoid heat loss and in particular to
avoid the possibility of freezing. Particular atten-
tion should be paid to pipes passing through
ventilated areas such as under floors, loft space
and void areas.
3A.6.2 AUTOMATIC BY-PASS
The appliance has a built-in automatic by-pass,
consequently there is no requirement for an exter-
nal by-pass, however the design of the system
should be such that it prevents boiler ‘cycling’.
3A.6.3 DRAIN COCKS
These must be located in accessible positions to
facilitate draining of the appliance and all water
pipes connected to the appliance.
3A.6.4 AIR RELEASE POINTS
These must be positioned at the highest points in
the system where air is likely to be trapped. They
should be used to expel trapped air and allow
complete filling of the system.
3A.6.5 EXPANSION VESSEL
The appliance has an integral expansion vessel to
accommodate the increased volume of water when
the system is heated. It can accept up to 10 litres of
expansion from within the system, generally this is
sufficient, however if the system has an unusually
high water content, it may be necessary to provide
additional expansion capacity (see 6.19).
3A.6.6 FILLING POINT
A method for initial filling of the system and replacing
water lost during servicing etc. is required (see fig.
14). You should ensure this method of filling com-
plies with the local water authority regulations.
3A.6.7 LOW PRESSURE SEALED SYSTEM
An alternative method of filling the system would
be from an independent make-up vessel or tank
mounted in a position at least 1 metre above the
highest point in the system and at least 5 metres
above the boiler (see fig. 5).
The cold feed from the make-up vessel or tank
must be fitted with an approved non-return valve
and stopcock for isolation purposes. The feed pipe
should be connected to the return pipe as close to
the boiler as possible.
3A.6.8 FREQUENT FILLING
Frequent filling or venting of the system may be
indicative of a leak. Care should be taken during
the installation of the appliance to ensure all
aspects of the system are capable of withstanding
pressures up to at least 3 bar.
3A.7
ELECTRICAL SUPPLY
The appliance is supplied for operation on 230V @
50Hz electrical supply; it must be protected with a
3-amp fuse. The method of connection to the
mains electricity supply must allow for complete
isolation from the supply. The preferred method is
by using a double-pole switch with a contact
separation of at least 3mm. The switch must only
supply the appliance and its corresponding con-
trols, i.e. time clock, room thermostat, etc.
3A.8
MOUNTING ON A COMBUSTIBLE
SURFACE
If the appliance is to be fitted on a wall of combus-
tible material, a sheet of fireproof material must
protect the wall.
3A.9
TIMBER FRAMED BUILDINGS
If the appliance is to be fitted in a timber framed
building, it should be fitted in accordance with I.S.
813 and local Building Regulations.
The Institute of Gas Engineers publication (IGE/
UP/7) ‘Guide for Gas Installations in Timber Frame
Buildings’ gives specific advice on this type of
installation.
3A.10 INHIBITORS
use new text here!!!
Vokera recommend that an inhibitor - suitable for
use with copper and aluminium heat exchangers -
is used to protect the boiler and system from the
effects of corrosion and/or electrolytic action. The
inhibitor must be administered in strict accord-
ance with the manufacturers instructions*
.
*Water treatment of the complete heating system
- including the boiler - should be carried out in
accordance with I.S. 813 and the Domestic Water
Treatment Association’s (DWTA) code of practice.
3A.11 DECLARATION OF CONFORMITY
A Declaration of Conformity (as defined in I.S.
813) must be provided on completion of the in-
stallation.
A copy of the declaration must be given to the
responsible person and also to the gas supplier if
required.