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 spark generator and ignition electrode

Measurement:

Measure the resistance across the ignition lead.
Expect approximately 1.2kOhms.
Also visually inspect the condition of the lead checking the insulation is all sound.
Are the checks on the ignition lead satisfactory?