Set Appliance State:

Set Multimeter to Resistance Set meter to measure resistance
Isolate Mains Power to appliance as per TOPs P4
Ensure Appliance is switched OFF.
Disconnect the Ignition Box Connector.
Remove Ignition Box from Appliance and take off cover.

Measurement:

Locate 2 Amp Fuse inside Ignition Box, remove and check across Fuse, for a Short Circuit Resistance.
Note:
Replace Fuse, Ignition Box Cover and Connecting Plug after test.