Set Appliance State:

Set Multimeter to Resistance Set meter to measure resistance
Isolate Mains Power to appliance as per TOPs P4
Gain access to PCB (use insulation mat as required)

Measurement:

Remove the plug-on connector marked CON 1 FLOW SWITCH (black wires) on PCB 27.
Measure the resistance across the connector (NOT the pins on the PCB).
Replace plug after test.