Set Appliance State:
| Isolate Mains Power to appliance as per TOPs P4 |
Set Multimeter to Resistance 
Unclip the hall sensor from below the turbine then disconnect the harness from the hall sensor
Measurement:
Check for continuity (zero resistance) between the three wires at the hall sensor plug to pins 3 (blue), 4 (white) and 5 (red) at connector X22 on the PCB.
Isolate as per TOPs P4
and refit as necessary