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INSTALLATION & SERVICING INSTRUCTIONS FOR WORCESTER BOSCH
8-716-106-252a (03.05)
7
MAINS SUPPLIES
ELECTRIC SUPPLY:
Supply: 230V - 50Hz
Cable: PVC insulated 0.75mm² (24 x 0.2mm)
temperature rated to 90°C
Protection IP20
External 5A fuse to BS1362
The appliance must be earthed
All pipes to the boiler must be cross-bonded
It must be possible to isolate the appliance from
the electric supply with at least a 3mm contact
separation in all poles supplying the appliance
Wiring between the appliance and the electrical
supply must comply with IEE wiring regulations
and any local regulations which may apply for
fixed wiring to a stationary appliance
Any system connected to the boiler must not
have a separate electricity supply
WATER SUPPLY:
The following are general requirements and if
necessary the advice of the local water company
should be sought before fitting the appliance.
The appliance cold water supply should be the
first connection off the water main where
possible.
Water Mains Pressure:
Minimum dynamic mains water pressure 1.2 bar
for maximum performance
Maximum mains fed water pressure 10 bar. If
necessary, fit a pressure reducing valve
IMPORTANT: Non-return, back flow
prevention devices (including those
associated with water meters) fitted to the
mains water supply can cause a pressure
build up which could damage the boiler and
other household appliances.
Where the water main supply has a non-return,
back flow prevention valve fitted, a mini expansion
vessel (A) should be connected to the mains
water inlet pipe (B) between the non-return valve
(C) and the boiler (D) as shown opposite.
Use in hard water areas:
Normally there is no need for water treatment to
prevent scale formation as the maximum temperature
of the heat exchanger is limited by the electronic
control circuit.
In areas where the temporary water hardness
exceeds 200ppm, consideration may need to be
given to the fitting of a scale prevention device. In
such circumstances, the advice of the local water
authority should be sought.
MAINS SUPPLIES
D
C
A
B
MAINS WATER EXPANSION VESSEL:
A - Mini expansion vessel, part No. 7 716 192 105
B - Water Main supply pipe
C - Non-return valve
D - Boiler
