Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4
Set Multimeter to Resistance Set meter to measure resistance
Remove the ignition lead from the PCB and from the spark electrode

Measurement:

Measure the resistance of the ignition lead from one end to the other.
Expect approximately 1kOhm.
Also visually inspect the condition of the lead.
Is the lead in good condition and is the resistance measured as expected?