This is a temporary pause where the boiler rests for a few minutes to prevent any unnecessary wear and tear from switching the burner on and off too frequently.

Diagnostics code: Setting the burner anti-cycling time

What causes this fault?

This occurs because the boiler has reached its required temperature too quickly and needs to pause before firing up again. It happens when the heat produced by the burner cannot be carried away fast enough, often because your radiators are already warm or the system's circulation is restricted. The boiler enters this brief rest period to prevent components from wearing out due to constant stopping and starting.