Set Appliance State:
| Isolate Mains Power to appliance as per TOPs P4 |
Set Multimeter to AC Volts 
CH Demand
Gain access to PCB (use Insulation Mat as required)
Ensure all external controls are calling
Ensure all external controls are calling
| WARNING! - Mains voltage is expected during test follow TOPs P4 live testing procedure |
Measurement:
Measure the AC voltage between terminal 4 on connector RT 230V and terminal N on connector 230V.
Expect mains voltage.
Is the voltage measured as expected?
Expect mains voltage.
Is the voltage measured as expected?
Isolate as per TOPs P4
and refit as necessary