26
0020003579A
IMPORTANT.
On completion of the Fault Finding task which has required the breaking and remaking of the electrical connections,
the continuity, polarity, short circuit and resistance to earth checks must be repeated using a suitable multimeter.
WARNING:
The multifunctional control and fan operate on mains voltage, the terminal will be live.
9 Fault Finding
Diagram 8.12
Diagram 8.11
BURNER
INJECTOR
GRAPHITE
COATED
NUT(2)
0939
8 Servicing
ELECTRODE
+
-
SPARK GAP
= 3.6 1.1
SECURING
SCREW
12026
Diagram 9.1
ELECTRICAL FAULT FINDING
12518
No
No
No
Before carrying out fault finding, ensure that gas, electricity and water are available to the boiler.
Ensure that any external controls are calling for heat and circuit water is cold.
If Reset/Standby indicator is lit - check water system for overheating, reset by turning temperature
control knob off and on. If the indicator coding is showing an ignition failure, reset the boiler by
turning the control knob off and on. Do not operate the boiler without combustion chamber front fitted.
Control Knob at '0'
Apply heating demand
(turn potentiometer clockwise)
Power ON at isolation switch
Does the unit begin to spark
Replace PCB
Does the fan start
Is there an INDICATOR sequence
Is there an INDICATOR sequence
Turn Gas ON
Is the Gas turned ON
Replace PCB
Replace PCB
Correct Operation
Does the burner light
Refer to table
Refer to table
Switch OFF
Remake connections
Restart diagnosis
Are the HT & Earth
connections made
Yes
Yes
Yes
Yes
Yes
Yes
No
No
Refer to table
Yes
Yes
Yes
Yes
No
No
No