Set Appliance State:
| Isolate Mains Power to appliance as per TOPs P4 |
Set Multimeter to AC Volts 
CH Demand
Remove controls cover as necessary
User Display control set to HW and CH
User Display control set to HW and CH
| WARNING! - Mains voltage is expected during test follow TOPs P4 live testing procedure |
Measurement:
Measure the voltage between the Blue wire at connector X3 and a suitable neutral with the connector attached to the PCB.
Mains voltage is expected.
Mains voltage is expected.
Isolate as per TOPs P4
and refit as necessary