Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4
Set Multimeter to AC Volts Set meter to measure AC Volts
Gain access to lower PCB panel
External controls (if fitted) calling for preheat
WARNING! - Mains voltage is expected during test follow
TOPs P4 live testing procedure
Mains Power On

Measurement:

Measure the voltage between HW on the yellow connector (marked LR with a tap symbol) and mains neutral.
Mains voltage expected.
Note:
If no external controls are fitted a link should be present between L and Lr.