Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4
Set Multimeter to Resistance Set meter to measure resistance
Remove connector J3 from the PCB

Measurement:

Measure the resistance between pins 6 and 7 (black) on connector J3.
Is open circuit or continuity/zero resistance measured?
Note:
If a frost thermostat is fitted wires will be present in pins 6 and 7.