Set Appliance State:
| Isolate Mains Power to appliance as per TOPs P4 |
Set Multimeter to Resistance 
Remove connector X18 from the PCB
Measurement:
The resistances on connector X18 should conform approximately to the table below:
| CON X18 (pump main supply) | Expected Resistance | Brown to Blue | 156 Ohms |
| Blue to Earth | Greater than 1 MOhm |
| Brown to Earth | Greater than 1 MOhm |
Isolate as per TOPs P4
and refit as necessary