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br BROWN
b BLUE
wh WHITE
KEY
bk BLACK
or ORANGE
3 WAY SOCKET CONNECTIONS
PCB CONNECTIONS
X4
r
b
wh
bk
y
gr
bk
bk
POT. TEMP.
CONTROL
LOCKOUT
LED
THERMISTOR
BURNER ON
LED
X5
9 Fault Finding
Diagram 9.2
FUNCTIONAL FLOW
9610
Refer to electrical fault finding chart, diagram 9.1 and functional
flow wiring diagram 9.2.
On completion of the fault finding task which has required the
breaking and remaking of electrical connections, the checks for
earth continuity, short circuit, polarity and resistance to earth
must be repeated.
9.2 Electrical Fault Finding Back Boiler
Refer to diagram 9.1.
9.3 Flue Blockage Safety Device and Ignition
Fault Finding
To check the safety device and ignition, refer to fault finding
chart, diagram 9.1.
br BROWN
b BLUE
wh WHITE
KEY
bk BLACK
or ORANGE
3 WAY SOCKET CONNECTIONS
PCB CONNECTIONS
SPARK
ELECTRODE
SENSE
HV
X2
FUSE
F1 400mA
SLOW
L
N
bk
wh
bk
PILOT
SOLENOID
LINK (OVERHEAT THERMOSTAT
IF FITTED)
MAIN
SOLENOID
br
b
b
b
or
X3
X1
X1
9609
Summary of Contents for BBU 45/4
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