Set Appliance State:
Set Multimeter to AC Volts 
CH Demand
Isolate Mains Power to appliance as per TOPs P4
Remove diverter valve head
Remove diverter valve head
| WARNING! - Mains voltage is expected during test follow TOPs P4 live testing procedure |
Measurement:
With heating calling measure voltage across terminal 6 (black wire) and terminal 2 (blue wire) at the connector on the diverter valve head.
Expected voltage approximately 28 Volts AC.
Expected voltage approximately 28 Volts AC.
Isolate as per TOPs P4
and refit as necessary