Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4
Set Multimeter to Resistance Set meter to measure resistance
Removed electrode assembly
Disconnect ignition leads from spark generator, note connections

Measurement:

Thoroughly check the spark electrodes & leads for wear, contamination, cracks, damage & spark gap is approximately 4mm.
Confirm continuity of electrodes & leads (see note).
Expected resistance continuity (zero resistance).