Set Appliance State:
| Isolate Mains Power to appliance as per TOPs P4 |
Set Multimeter to Resistance 
Disconnect 1 wire from the overheat thermostat
Measurement:
Measure the resistance between the two terminals of the overheat thermostat.
Resistance should be short circuit (zero resistance).
Resistance should be short circuit (zero resistance).
Isolate as per TOPs P4
and refit as necessary