PRE-INSTALLATION
6 720 804 532 (2012/09)
10
INHIBITOR
Add a suitable inhibitor or combined inhibitor/anti-freeze, if the system
is exposed to freezing conditions, to the heating system in accordance
with the DWTA code of practice and manufacturer‘s guidelines.
WATER TREATMENT PRODUCTS
Suitable water treatment products can be obtain from the following
manufacturers:
ARTIFICIALLY SOFTENED WATER
It is possible to have an ion exchange water softener fitted to the cold
water system of the property. However, the boiler requires an untreated
cold water connection taken from the mains supply, before the water
softener, to the primary water filling point of the heating system.
Alternatively there are water softening/treatment devices that do not
adjust or alter the pH levels of the water. With these devices it may not
be necessary to provide an untreated water by-pass to the primary water
filling point of the heat system.
3.2
MAINS SUPPLY
3.2.1
ELECTRICAL SUPPLY
• Supply: 230V - 50 Hz, 140 Watts
• Cable: PVC insulated 0.75 mm
2
(24 x 0.2 mm) temperature rated to
90 °C.
• External 3A fuse to BS1362.
• The appliance must be earthed.
• This appliance must not be connected to a three phase supply.
• IPX4D.
• Wiring must comply with the latest edition of BS 7671 (IEE wiring
regulations).
3.2.2
GAS SUPPLY
• Boilers using Natural Gas (NG) must be connected to a governed
meter.
• Liquid Petroleum Gas (LPG) must be connected to a regulator.
• Installation and connection of the gas supply to the boiler must be in
accordance with BS6891.
• The meter or regulator and pipe work to the meter must be checked,
preferably by the gas supplier.
This is to ensure that the equipment is in good working order and can
meet the gas flow and pressure requirements, in addition to the
demand from any other appliance being served.
3.3
WATER SYSTEM AND PIPE WORK
PLASTIC PIPE WORK:
• Any plastic pipe work must have a polymeric barrier with 600mm
(minimum) length of copper pipe connected to the boiler.
• Plastic pipe work used for underfloor heating must be correctly
controlled with a thermostatic blending valve limiting the temperature
of the circuits to approximately 50 °C.
PRIMARY SYSTEMS CONNECTIONS/VALVES:
• All system connections, taps and mixing valves must be capable of
sustaining a pressure up to 3 bar.
• Radiator valves should conform to BS2767:10.
• All other valves should conform to BS1010.
• Thermostatic radiator valves (TRV’s) must be used on all radiators
within the sleeping accommodation but not the radiator where the
room thermostat is sited. This must be fitted with lock-shield valves
and left open.
• A drain cock is required at the lowest point in the system.
• An air vent is required at all the high points in the system.
SEALED PRIMARY SYSTEM:
• The CH sealed system must be filled using a WRAS approved filling
loop or comply with figure 4 for system fill.
• Where the system volume is more than 100 litres or exceeds 2.65 bar
at maximum heating temperature, an extra expansion vessel (2) must
be fitted as close as possible to the appliance in the central heating
return.
• Pressurise the extra expansion vessel (2) to the same figure as the
expansion vessel built into the appliance.
•
Do not use galvanised pipes or radiators
.
SYSTEM FILL
Fig. 4
System fill
WARNING:
Sealing agents
▶ Normally the addition of sealing agents to the system
water is not permitted as this can cause problems
with deposits left in the heat exchanger.
▶ In cases where all attempts to find a micro leak have
failed, Worcester, Bosch Group supports the use of
Fernox F4 leak sealer.
FERNOX
0870 601 5000 or www.fernox.com
SENTINEL
0800 389 4670 or www.sentinel-solutions.net
NOTICE:
This is reduced to IP20 if the following
mechanical timers are fitted;
7 716 192 036 or 7 716 192 037 or the FW100
controller 7 716 192 067.
NOTICE:
12, 15, 18 and 24 iSystem models.
▶ Provided that the correct gas supply working
pressure and gas rate can be achieved (see technical
data on page 6, Check gas inlet pressure on page 31,
also refer to B.S. 6891)
▶ Then it may be possible to reduce the gas supply pipe
diameter to 15mm.
The boiler is equipped with an internal by-pass.
The internal bypass is not intended to be a substitute for
an external system bypass.
An external automatic bypass should be used if the
system flow can be significantly adjusted or stopped by
zone valves and thermostatic radiator valves (TRV).
NOTICE:
Artificially softened water must not be used to
fill the central heating system.
CV = Check Valve
SV = Stop Valve
SV
SV
Test point
Temporary hose
Hose union
CV
CV
Heating
return
Mains
supply
SYSTEM MAKE UP
AA = Auto Air vent
CV = Check Valve
SV
CV
AA
Make up
vessel
Heating
return
1000 mm (39 in)
above the highest
point of the system.
Fill point
6720644743-08.1W
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