Set Appliance State:

Mains Power Off
Set Multimeter to DC Volts Set meter to measure DC Volts
CH Demand
Gas On
WARNING! - Mains voltage is expected during test follow
TOPs P4 live testing procedure
Mains Power On

Measurement:

Measure the voltage between blue (7) at connector X401 and earth.
Expect approximately 13 Vdc or greater.
Is the voltage measured as expected?
Notes:
1. The voltage may vary but it should remain above 13 Vdc.
2. The test must be completed within 60 seconds of turning the mains power on (if the electrical isolation switch is not near the appliance it is acceptable to use the selector switch on the front of the appliance).