Set Appliance State:
| Isolate Mains Power to appliance as per TOPs P4 |
Set Multimeter to Resistance 
Remove X3 connector from the PCB and the
connector to spark generator
connector to spark generator
Measurement:
Measure the resistance of each wire of the harness.
The resistance should conform to the table below:
The resistance should conform to the table below:
| Wires | Resistance in Ohms | Blue - Blue | Continuity (zero resistance) |
| Brown - Brown | Continuity (zero resistance) |
| Green/Yellow - Boiler chassis | Continuity (zero resistance) |
Isolate as per TOPs P4
and refit as necessary