Set Appliance State:
| Isolate Mains Power to appliance as per TOPs P4 |
Set Multimeter to Resistance 
Remove the spark electrode assembly
Measurement:
Measure the resistance of the spark electrode from end to end.
Expect continuity/zero resistance.
Measure the spark gap between the electrodes which should be approximately 5mm.
Check the electrode has not warped or distorted by checking the measurement to the tip from a flat surface is approximately 12mm as shown and that it looks like the image.
Also thoroughly inspect the ignition electrode for good general condition and that the ceramic is not cracked.
Expect continuity/zero resistance.
Measure the spark gap between the electrodes which should be approximately 5mm.
Check the electrode has not warped or distorted by checking the measurement to the tip from a flat surface is approximately 12mm as shown and that it looks like the image.
Also thoroughly inspect the ignition electrode for good general condition and that the ceramic is not cracked.
Isolate as per TOPs P4
and refit as necessary