Set Appliance State:
Isolate Mains Power to appliance as per TOPs P4
Disconnect connector PL1 from the PCB
Disconnect connector PL1 from the PCB
Measurement:
Measure the resistance between the two terminals with white wires at removed connector PL1.
Reconnect connector PL1 after this test.
Reconnect connector PL1 after this test.

Isolate as per TOPs P4
and refit as necessary