Set Appliance State:
Set Multimeter to Resistance 
Isolate Mains Power to appliance as per TOPs P4
Measurement:
Inspect electrode lead for good general condition, signs of shorting and carry out resistance check on the lead.
ELECTRODE LEAD INSPECTION
Note:
Electrode lead runs from the electrode to the spark generator on the gas valve PCB
Electrode lead runs from the electrode to the spark generator on the gas valve PCB