Supplied By www.heating spares.co Tel. 0161 620 6677
7
221764B
FRONT CLEARANCE
Diagram 1.5
0906
700 (27
1/
2
in.)
BOILER
WALL OR
FIXTURE
1 General Data
2 Water Systems
Diagram 2.1
0869
27metre
Max.
PUMP
To Heating
Circuit
INDIRECT
CYLINDER
22mm VENT
15mm COLD FEED
REFER TO BS 5546
28mm
Distributor tube in
pumped return
connection
BOILER
CL
DRAIN OFF
COCK
Diagram 2.2
FULLY PUMPED SYSTEM
(DIAGRAMMATIC)
0870
1 metre
MIN.
27metres
MAX.
PUMP
To Heating
Circuit
TO INDIRECT
CYLINDER
22mm VENT
15mm
COLD FEED
Distributor tube in
pumped return
connection
BOILER
CL
DRAIN OFF
COCK
A special top casing, part No. 424820, can be purchased to
enable the boiler casings to be arranged flush with 600mm
(23
5
/
8
in) deep work tops and kitchen units.
Where the installation of the boiler will be in an unusual location,
special procedures are necessary, the current issue of BS6798
gives guidance on this.
A compartment used to enclose the boiler must be designed
and constructed specifically for this purpose. An existing
cupboard or compartment modified for the purpose may be
used. Details of essential features of cupboard design are given
in the current issue of BS6798.
If the boiler is to be installed in a compartment, make sure that
nothing will obstruct the openings/vents in the compartment.
1.9 Heating System Controls
The heating system should have installed: a programmer and
room thermostat controlling the boiler.
Thermostatic radiator valves may be installed in addition to the
room thermostat.
2.1 Water Pressure Head
This boiler shall only be connected to a cistern supply, with a
minimum head of 1 metre (3ft) and a maximum of 27 metres
(90ft) and having an open vent in the system.
The boiler must not be connected to a sealed water system.
2.2 Inhibitor
Attention is drawn to the current issue of BS5449 and BS7593
on the use of inhibitors in central heating systems.
If an inhibitor is to be used in the system, contact should be
made with an inhibitor manufacturer so they can recommended
their most suitable product.
When using in an existing system take special care to drain the
entire system, including the radiators, then thoroughly cleaning
out before fitting the boiler, whether or not adding an inhibitor.
2.3 Gravity Domestic and Pumped Heating
It is recommended that a cylinder thermostat is used to prevent
the stored water temperature becoming unnecessarily high.
The primary flow and return must be 28mm. The
installation must comply with the current issue of BS5546 and
BS6700, see diagram 2.1.
If the above conditions cannot be met, it is suggested that a fully
pumped system be used.
Fully Pumped System
Where a single pumped, flow and return is taken from the boiler,
refer to diagram 2.2.
2.5 Circulation Pump
The pump should be set to give a temperature difference of
11
o
C (20
o
F) across the system. At the appropriate flow rate the
resistance through the boiler can be found from the pressure
loss graph, diagram 2.3.
If possible use a pump with integral valves, if not fit valves as
close as possible each side of the pump.
Note: If the pump is to be fitted inside the boiler casing a heat
shield kit is required. Kit No. 425839.
Note: For further information, see The Building Regulations
1991 - Conservation of fuel and power, 1995 edition - Appendix
G, table 4b.