Set Appliance State:
| Isolate Mains Power to appliance as per TOPs P4 |
Set Multimeter to Resistance 
Disconnect inline connector to the overheat thermostat
(connects grey wire to a black wire, with a clear plastic cover)
(connects grey wire to a black wire, with a clear plastic cover)
Measurement:
Measure the resistance between the disconnected grey spade and the grey wire at CN102 on the ignition PCB.
Resistance should be short circuit (zero resistance).
Resistance should be short circuit (zero resistance).
Isolate as per TOPs P4
and refit as necessary