Set Appliance State:
Set Multimeter to AC Volts 
CH Demand
Isolate Mains Power to appliance as per TOPs P4
Operating Switch in Heating & Water position
Operating Switch in Heating & Water position
| WARNING! - Mains voltage is expected during test follow TOPs P4 live testing procedure |
Measurement:
Is there Mains Voltage present across push in connector CN1 connection (L Brown) on Ignition Control board and connector X7 connection 2 (N Blue) on Main Driver board?
Isolate as per TOPs P4
and refit as necessary