Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4
Set Multimeter to AC Volts Set meter to measure AC Volts
CH Demand
Gain access to incoming terminal strip as necessary
WARNING! - Mains voltage is expected during test follow
TOPs P4 live testing procedure
Mains Power On

Measurement:

Measure the AC voltage between terminal 1 and terminal 5 at the incoming terminal strip.
Expect mains voltage.
Is the voltage measured as expected?