Set Appliance State:

Mains Power Off
Ensure no CH or DHW demands
WARNING! Mains voltage is expected during test, follow TOPs P4 live testing procedure
Mains Power On

Observation:

With no demands the boiler should enter standby, the fault indicator light / reset button should not flash and neither the pump or fan should run.
Does the boiler enter standby as above?
Note:
In noisy environments it may be necessary to remove the combustion chamber to visually see if the fan is running.