Set Appliance State:

Mains Power Off
Set Multimeter to AC Volts Set meter to measure AC Volts
Main switch in ON position
WARNING! Mains voltage is expected during test, follow TOPs P4 live testing procedure
Mains Power On

Measurement:

Depress Gas Control Valve Knob whilst measuring Mains voltage across connection 8 on Ignition Microswitch and Neutral.