Set Appliance State:
| Isolate Mains Power to appliance as per TOPs P4 |
Set Multimeter to DC 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 DC voltage between terminal 8 on connector RT24V and terminal N at connector 230V.
Expect approximately 24 vdc.
Is the voltage measured as expected?
Expect approximately 24 vdc.
Is the voltage measured as expected?
Isolate as per TOPs P4
and refit as necessary