Set Appliance State:

CH & DHW temperature controls set to MAX
WARNING! - Mains voltage is expected during test follow
TOPs P4 live testing procedure
Mains Power On

Observation:

Allow the boiler to complete its 2 minute self-check & purge cycle,
once completed the display should indicate boiler standby (see note).
 
The fan should not be running constantly during the self check (may run briefly at power-on).
 
If preheat is enabled, indicated by P or a blinking P in the display after self check & purge cycle has completed, then this will need to disabled before continuing, click HERE for guidance.