Set Appliance State:

Turn Hot Water Tap On
ECO mode on (ECO in display)
Gas On
WARNING! - Mains voltage is expected during test follow
TOPs P4 live testing procedure
Mains Power On

Observation:

Reset boiler as necessary (press reset button for 1 second).
Does the burner ignite and establish correctly?
Note:
Spark electrode and burner can be observed through the sight glass on the front of the appliance combustion chamber. The spark should be seen by looking slightly upwards and to the right through the sight glass.