Set Appliance State:
| Isolate Mains Power to appliance as per TOPs P4 |
Set Multimeter to AC Volts 
CH Demand
User display control set to HW and CH
Remove control box cover if necessary
Remove control box cover if necessary
Gas On
| WARNING! - Mains voltage is expected during test follow TOPs P4 live testing procedure |
Measurement:
Allow the ignition sequence to commence and burner to ignite.
Measure the voltage between the red wire on connection X13 and the neutral at the incoming mains terminal strip, with the connector X13 attached to the PCB.
Measure the voltage between the red wire on connection X13 and the neutral at the incoming mains terminal strip, with the connector X13 attached to the PCB.
Isolate as per TOPs P4
and refit as necessary