6
Mynute 24m
3.5
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.
3.6
WATER CIRCULATION
Detailed recommendations are given in BS 5449
Part 1 and BS 6798. The following notes are for
general guidance only.
3.6.1 PIPEWORK
It is recommended that copper tubing to BS 2871
Part 1 is 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 attention
should be paid to pipes passing through ventilated
areas such as under floors, loft space, and void
areas.
3.6.2 AUTOMATIC BY-PASS
The appliance has a built-in automatic by-pass,
consequently there is no requirement for an external
by-pass, however the design of the system should
be such that it prevents boiler “cycling” and is
compliant with current Building Regulations.
3.6.3 DRAIN COCKS
These must be located in accessible positions to
facilitate draining of the appliance and all water
pipes connected to the appliance. The drain cocks
must be manufactured in accordance with BS 2879.
3.6.4 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.
3.6.5 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 8 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).
3.6.6 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.
3.6.7 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.
3.7
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 appli-
ance and its corresponding controls, i.e. time clock,
room thermostat, etc. Alternatively an un-switched
shuttered socket with a fused 3-pin plug both
complying with BS 1363 is acceptable.
3.8
LOCATION
This appliance is suitable only for internal applica-
tions and therefore must not be installed externally
to the property it serves.
3.9
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.
3.10
TIMBER FRAMED BUILDINGS
If the appliance is to be fitted in a timber framed
building, it should be fitted in accordance with the
Institute of Gas Engineers publication (IGE UP/7)
“Guide for Gas Installations in Timber Frame Build-
ings”.
Fig. 5a
Make-up
vessel or tank
Automatic
air-vent
Non-return
valve
Stopcock
5.0 metres minimum
Heating
return