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 |
Measurement:
If boiler is in lockout reset it then turn mains power OFF
then back ON so that it starts the appliance self check.
(AP shown on display).
Measure the voltage between the blue and brown wires on the right hand side of X11 on the PCB.
Mains voltage should be present at 5 second intervals as the boiler carries out its self check.
then back ON so that it starts the appliance self check.
(AP shown on display).
Measure the voltage between the blue and brown wires on the right hand side of X11 on the PCB.
Mains voltage should be present at 5 second intervals as the boiler carries out its self check.
Isolate as per TOPs P4
and refit as necessary