Set Appliance State:

Gas Off
Set Multimeter to AC Volts Set meter to measure AC Volts
Isolate Mains Power to appliance as per TOPs P4
Gain access to PCB as necessary
WARNING! Mains voltage is expected during test, follow TOPs P4 live testing procedure
Mains Power On

Measurement:

Measure AC Voltage across Relay 1 connection 7 (Orange) and N (Blue) on the Appliance Terminal Block.