Bosch 12/18 User Manual

Page of 52
MAINS SUPPLIES
ELECTRIC SUPPLY:
•  Supply: 230V - 50Hz.
•  Cable: PVC insulated 0.75mm
2
(24 x
0.2mm) temperature rated to 90°C.
•  Protection IP45.
•  External 5A fuse to BS 1362.
•  The appliance must be earthed.
•  Please refer to IEE regulations for cross
bonding requirements.
•  It must be possible to isolate the appliance
from the electric supply with at least a 3mm
contact separation in both 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 electrical 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.
•  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) must 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 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 WATER EXPANSION VESSEL:
A - Mini expansion vessel, part No. 7 716 102 105
B - Mains water inlet
C - Non-return valve 
D - Boiler
A
B
C
D
MAINS SUPPLIES
INSTALLATION & SERVICING INSTRUCTIONS FOR WORCESTER GREENSTAR HEATSLAVE EXTERNAL 12/18-18/25-25/32
8 716 113 389b (09/07) 
8
P
R
E -
IN
ST
AL
LA
TI
O
N
12/18kW
Water Mains Pressure:
Minimum dynamic mains water pressure for 
optimum performance. 
1.5 bar
1.2 bar
0.9 bar
18/25kW
25/32kW
IMPORTANT: The appliance provides a permanent external electrical supply
for servicing and must therefore be fed via a circuit breaker incorporating
earth leakage protection.