Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4
Set Multimeter to Resistance Set meter to measure resistance
Gain access to PCB (use Insulation Mat as required)
CH temperature selector to MAX
Disconnect connector X15 from PCB

Measurement:

Measure resistance across connection 2 and connection 3 (white wires) on connector X15 on the main PCB.
Resistance should be short circuit.