Set Appliance State:

Mains Power Off
CH & DHW temperature controls set to MAX
Ensure No demands & boiler is cool
For guidance regarding programmer operation click HERE
WARNING! - Mains voltage is expected during test follow
TOPs P4 live testing procedure
Mains Power On

Observation:

Allow the boiler to complete its self-check & purge cycle, this will take approximately 2 minutes, once completed the time should be displayed (see note).