Your boiler is currently running a self-diagnostic check to ensure the ignition system is sparking correctly before it starts up.

Ignition test – checking the igniter spark

What causes this fault?

This is a brief, automated check that occurs when the boiler prepares to light the burner. It happens because the system's control board needs to verify that the ignition electrodes are capable of creating a spark before releasing gas. It is not an indication of a breakdown, but rather a standard safety protocol being carried out by the internal computer.