Set Appliance State:

Mains Power Off
Turn Hot Water Tap On
Selector switch to HOT WATER position
Gas On
WARNING! - Mains voltage is expected during test follow
TOPs P4 live testing procedure
Mains Power On

Observation:

Depress the gas control knob and allow the boiler to execute its purge delay period. (Fan runs at high speed for approximately 20 seconds before sparking begins).
When purge period is complete, observe sparking at the electrode through the sight glass, the pilot should ignite.
Keep the gas control knob depressed for a further 20 seconds after the pilot has lit. Slowly release the control knob. Does the pilot remain alight?