that the hearth must extend in front of the stove by at least 300mm
(12 inches) and to the sides of the stove by at least 150mm (6
inches). If in doubt as to the positioning of the stove expert advice
should be sought either from the supplier or the local building
inspector.
The fireplace must allow good circulation of air around the appliance
to ensure that maximum heat is transferred to the room and also to
prevent the fireplace from overheating. A gap of 150mm (6 inches)
each side and 300mm (12 inches) above the appliance should give
sufficient air circulation. If a wooden mantelpiece or beam is used in
the fireplace it should be a minimum of 460mm (18 inches), and
preferably 600mm (24 inches) from the appliance. In some situations
it may be necessary to shield the beam or mantelpiece to protect it.
In order for the fire to operate correctly there must be an air gap
behind the appliance of at least 40mm, but be aware that this
distance will need to be greater in some cases to meet Building
Regulation requirements.
The central heating system must comply with BS:5449 part 1.
The installation of any electrical services during the installation of this
boiler and the associated heating system must be carried out by a
registered competent electrician and in accordance with the
requirements of the latest issue of BS 7671.
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:1556 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. 5 and 6. 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 return is used an injector tee must be
incorporated into the system as shown in Fig. 7. This will ensure that
a good domestic hot water supply is maintained when the central
heating pump is operating.
The system must incorporate a gravity circuit which will normally
heat the domestic hot water and an unvalved radiator with an output
of at least 1 kW. When the appliance is not connected to a domestic
CENTRAL HEATING SYSTEM
Electrical connections
Central
Heating Return
Drain Cock at Lowest Point
Cold Water Tank
Circulating Pump
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
Drain Cock
Gravity Return 28mm
Gravity Flow 28mm
Indirect Hot Water Cylinder
Domestic Hot
Water Draw Off
Overflow
Overflow
Feed and Expansion Tank
22mm Open Vents
Gravity Radiator
Injector Tee
Central
Heating Flow
Minimum Return
Thermostat
Overflow
Domestic Hot Water
Draw Off
Gravity Return (28mm Pipe)
Central Heating
Return
Common
Return to Boiler
(28mm Pipe)
Fig. 7. Injector Tee.
Fig. 5. Typical Central Heating & Hot Water System
Using 4 Boiler Tappings
Fig. 6. Typical Central Heating & Hot Water System
Using 3 Tappings
Minimum Return Thermostat
INSTALLATION INSTRUCTIONS
®
charnwood
I S L A N D
10
