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 the boiler to enter fan lockout.
Measure the voltage between pin 3 (blue) and pin 4 (brown) on HV2 at the PCB within 1 minute of the appliance entering fan lockout.
Mains voltage should be present.
Note:
After 1 minute the voltage to fan assembly will no longer be present, if required reset the appliance and allow it to re-enter fan lockout to confirm the outcome of the test.
Measure the voltage between pin 3 (blue) and pin 4 (brown) on HV2 at the PCB within 1 minute of the appliance entering fan lockout.
Mains voltage should be present.
Note:
After 1 minute the voltage to fan assembly will no longer be present, if required reset the appliance and allow it to re-enter fan lockout to confirm the outcome of the test.
Isolate as per TOPs P4
and refit as necessary