Your boiler is performing a routine self-diagnostic purge or testing phase and is not currently experiencing a breakdown.

Minimum load: After successful ignition, the product is operated at minimum heat input.

What causes this fault?

This code appears because your boiler is running a brief self-test to ensure the system is stable at its lowest power setting. It occurs automatically during the startup sequence to verify that the internal components are functioning correctly before ramping up the heat. It is a sign that the boiler's internal computer is performing its standard safety and efficiency checks.