Set Appliance State:

Gas Off
Isolate Mains Power to appliance as per TOPs P4
Turn Hot Water Tap On
Remove electrode lead from spark generator
Set selector switch to ch/dhw
Dhw temperature control to max
WARNING! - Mains voltage is expected during test follow
TOPs P4 live testing procedure
Mains Power On

Observation:

Allow boiler to commence its ignition sequence.
Does sparking occur for approximately 5 seconds?

Caution:

Stand away from boiler when test in progress.
Note:
Lockout may occur after one attempt to ignite. If lockout occurs or the boiler is already in lockout then the reset will have to be carried out.