Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4
Set Multimeter to Resistance Set meter to measure resistance
Disconnect plug X14 from the PCB
Thermostat Operates at 105°C - Ensure appliance
is below this before continuing test

Measurement:

Measure the resistance of the two blue wires on
pins 1 and 2 of the X14 plug.
Expect a short / closed circuit.