HEARTH
The appliance must be installed on a
fireproof hearth and must be situated
at least 300 mm (12 inches) from any
combustible material. The positioning
of the appliance and the size of the
hearth are governed by building
regulations for Class 1 appliances.
These building regulations state that
the hearth must extend in front of the
appliance by at least 300 mm (12
inches) and to the sides by at least
150 mm (6 inches). If in doubt as to
the positioning of the appliance expert
advice should be sought either from
the supplier or the local building
inspector.
PREPARATION OF
FIREPLACE
Before fitting the appliance into an
existing fireplace remove the fireback
and any loose in-fill material.
The hearth, surround and opening for
the appliance must conform with Figs.
6 and 7. The flat area around the
opening must be a minimum of 750
mm wide and 660 mm high. Ensure
that the hearth and the base in the
opening are flat, level, and at right
angles to the surround.
Make two holes in the chimney breast,
one in the front to give access for
infilling and fixing the flue pipe, and
one in the side to give access for the
pipework.
CENTRAL HEATING
SYSTEM
The central heating system must
comply with BS:5449 part 1.
If the system is to be a combined
heating and domestic hot water system
then a double feed indirect hot water
storage cylinder to BS:1566 part 1
should be used. In order to prevent the
build up of scale and corrosion a
suitable inhibitor should be used. The
system must be correctly vented as
shown in Figs. 8 and 9. The height
differential between the header tank
and the appliance must not exceed
15.2 metres (50 feet).
If all four boiler tappings are used
then, if possible, diagonal pairs should
be connected for domestic hot water
and central heating. Where a common
Central Heating Flow
Central Heating Return
Drain Cock at Lowest Point
Drain Cock
Gravity Return 28mm
Gravity Flow 28mm
Indirect Hot Water Cylinder
Cold Water Tank
Overflow
Feed and Expansion Tank
22mm Open Vents
Gravity Radiator
Circulating Pump
Central Heating Return
Drain Cock at Lowest Point
Drain Cock
Gravity Return 28mm
Gravity Flow 28mm
Indirect Hot Water Cylinder
Domestic Hot Water Draw Off
Cold Water Tank
Overflow
Overflow
Feed and Expansion Tank
22mm Open Vents
Gravity Radiator
Circulating Pump
Injector Tee
Minimum Return Thermostat
Gravity Return
(28mm Pipe)
Central Heating Return
Common Return to Boiler
Central Heating Flow
Minimum Return
Thermostat
(28mm Pipe)
Overflow
Domestic Hot Water Draw Off
Fig. 8. Typical Central Heating & Hot Water System
Using 4 Boiler Tappings
Fig. 9. Typical Central Heating & Hot Water System
Using 3 Tappings
Fig. 10. Injector Tee.
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