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:
Allow boiler to enter fan lockout.
Measure the voltage between the brown wire marked 13.4
and the blue wire marked 13.5 at X11 on the PCB.
Mains voltage should be present.
Measure the voltage between the brown wire marked 13.4
and the blue wire marked 13.5 at X11 on the PCB.
Mains voltage should be present.
Isolate as per TOPs P4
and refit as necessary