Set Appliance State:
| Isolate Mains Power to appliance as per TOPs P4 |
Set Multimeter to AC Volts 
Gain access to PCB (use Insulation Mat as required)
| WARNING! - Mains voltage is expected during test follow TOPs P4 live testing procedure |
Observation:
Test 1:
Measure voltage between pin 9 (green wire) on connector ST9
at the PCB and a suitable earth point.
Expected voltage approximately 50V AC.
Test 2:
Turn hot water tap ON.
Measure the voltage between pin 9 (green wire) on connector ST9 at the PCB
and a suitable earth point as boiler goes through its ignition sequence.
When the burner ignites the voltage should drop from 50V to approx 40V AC.
Measure voltage between pin 9 (green wire) on connector ST9
at the PCB and a suitable earth point.
Expected voltage approximately 50V AC.
Test 2:
Turn hot water tap ON.
Measure the voltage between pin 9 (green wire) on connector ST9 at the PCB
and a suitable earth point as boiler goes through its ignition sequence.
When the burner ignites the voltage should drop from 50V to approx 40V AC.
