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 to CH and HW
User display control to CH and HW
| WARNING! - Mains voltage is expected during test follow TOPs P4 live testing procedure |
Measurement:
Measure the voltage between the Black wire at connector X3 and the neutral at the incoming mains terminal strip, with the connector X3 attached to the PCB.
Mains voltage is expected.
Mains voltage is expected.
Isolate as per TOPs P4
and refit as necessary