Set Appliance State:

Mains Power Off
Turn Hot Water Tap On
Gas On
WARNING! - Mains voltage is expected during test follow
TOPs P4 live testing procedure
Mains Power On

Observation:

Reset appliance as necessary (hold down both arrow buttons until display changes).
Listen carefully to the appliance as it goes through its ignition sequence.
Does the burner ignite and establish correctly?
This is confirmed when the flame symbol appears and remains on the display.
If the flame symbol does not appear after the burner ignites this indicates a rectification issue.
Once lit the flame should not baffle or be excessively noisy as this indicates a combustion issue.
Notes:
1. It can take up to 15 seconds for the initial ignition sequence to begin after a DHW demand.
2. It can take up to 40 seconds between ignition attempts.
3. If you wish to refer to fault codes click HERE.