NOTE:
The mains electrical supply to the boiler and
system wiring centre must be common and
through either a common fused double pole
isolator or a fused three pin plug and
unswitched socket.
The isolator shall be situated next to the
boiler for new systems and, where
practicable, replacement boilers.
The isolator must have a contact separation
of 3mm minimum between all poles. Any
system connected to the boiler must not
have a separate electrical supply.
External fuse 3 Amps.
When stripping wires ensure copper strands
do not fall into the control box.
Access to electrical connections:
Remove boiler casing to access control panel.
1 Remove screw (A) and swing the control
panel into the service position.
2 Remove the three screws (B) in the control
panel and remove the connections cover.
3 Unclip cable clamp (C).
4 Cut off the tapered cable entry to suit the
cable diameter.
5 Unscrew cable retaining screw (D).
Run the cable through the cable clamp (C)
ensuring there is ample cable to reach the
connectors. Tighten the cable retaining
screw D to secure the cable and replace
clamp C into the control panel.
6 Mains power 230 Volt connection ST10:
Separate wires from cable end and strip
to 6mm
Connect LIVE wire to terminal L
Connect NEUTRAL wire to terminal N
Connect EARTH wire to connector
NOTE: Make the EARTH wire longer so that
if the cable is snagged, the EARTH
wire is the last to be pulled out.
7 Optional frost thermostat connection ST6:
Connect frost thermostat supply wire to
terminal Fs
Connect frost thermostat return wire to
terminal F
R
8 230V room thermostat and/or external timer
ST10:
Remove link
Connect room thermostat LIVE supply to
terminal Ls
Connect room thermostat LIVE return to
terminal L
R
Connect room thermostat NEUTRAL to
terminal Ns
9 Refit all panels
Refer to manufacturers instructions when
connecting external parts to the wiring centre.
Worcester, Bosch Group cannot be held
responsible for wiring errors.
ELECTRICAL
CAUTION: ISOLATE THE MAINS
ELECTRICITY SUPPLY BEFORE STARTING
ANY WORK AND OBSERVE ALL RELEVANT
SAFETY PRECAUTIONS
INS
TALL
A
TION
INSTALLATION & SERVICING INSTRUCTIONS
31
ELECTRICAL
8 716 115 219c (03.2010)
L
N
L
ST10
N
E
EARTH =
E
LIVE =
L
NEUTRAL =
N
230 V
L
R
L
S
N
S
6
3
AND
/OR
L
N
ST10
L
R
L
S
N
S
S
L
N
S
F
R
F
S
N
P
L
P
FROST
THERMOSTAT
ST10
ST6
SWITCHED LIVE =
S
3
4
5
6
7
8
6 7
20 6
14562-04.
1O
C
D
D
2
1
A
B
