Set Appliance State:

Gas Off
Isolate Mains Power to appliance as per TOPs P4
DHW Demand
Set performance tester to pressure setting
Remove tube from P2 on the air pressure sensor and connect air pressure test kit with t piece included in kit to the syringe and the negative on performance tester
WARNING! Mains voltage is expected during test, follow TOPs P4 live testing procedure
Mains Power On

Observation:

Run the boiler with DHW tap on with the gas off on the isolation valve.
Allow the fan to run.
Slowly start to pull out the syringe to create a pressure on the performance tester.
As you reach 0.5 mbar sparking should start to occur.
NOTE:As the APS test kit instructions state you can increase the charge pressure by 50% without damaging the APS so in this case you can take it up to 0.75 mbar for test without damaging it.