Set Appliance State:

Mains Power Off
Ensure NO demands are present
WARNING! - Mains voltage is expected during test follow
TOPs P4 live testing procedure
Mains Power On

Observation:

When power is switched on the boiler will run a self-check.
Allow 15 seconds for self-test to complete.
When self-check has completed successfully, ON will be displayed.
Has SC disappeared from the display?
Note:
1. If after self-check has completed, a fault code other than SC is displayed, then CLICK HERE.