Set Appliance State:
| Isolate Mains Power to appliance as per TOPs P4 |
Set Multimeter to Resistance 
Remove Connector X13 from the PCB
Remove diverter valve head from body
Remove diverter valve head from body
Measurement:
Observe the position of the spindle in the diverter valve head.
If the spindle is extended (Heating Position) expect approximately 6Kohms between Black and White wires.
If the spindle is retracted (Hot Water Position) expect approximately 6Kohms between Red and Black wires.
The spindle may be not be fully in one position so also test for 6Kohm between Black and Red / Black and White wires, and continuity between Red and White Wires.
If the spindle is extended (Heating Position) expect approximately 6Kohms between Black and White wires.
If the spindle is retracted (Hot Water Position) expect approximately 6Kohms between Red and Black wires.
The spindle may be not be fully in one position so also test for 6Kohm between Black and Red / Black and White wires, and continuity between Red and White Wires.
Isolate as per TOPs P4
and refit as necessary