Set Appliance State:
| Isolate Mains Power to appliance as per TOPs P4 |
Set Multimeter to Resistance 
Remove X8 from the PCB and connector at DHW flow turbine
Measurement:
Measure the resistance of each wire of the harness.
The resistance should conform to the table below:
The resistance should conform to the table below:
| Wire | Resistance in Ohms | Red - Red | Continuity (zero resistance) |
| Blue - Blue | Continuity (zero resistance) |
| Black- Black | Continuity (zero resistance) |
Isolate as per TOPs P4
and refit as necessary