Your boiler is temporarily paused because it is running a self-diagnostic check on its internal temperature sensors to ensure they are working correctly.

Automatictestprogramme:Returntemperaturesensor,heatingdemandsblocked.

What causes this fault?

This code appears when the boiler's internal computer notices a potential discrepancy between the flow and return temperature readings. It triggers a brief pause to double-check that the sensors are reporting accurately before allowing the burner to fire up again. Usually, this is caused by a sensor that is starting to drift out of its correct calibration or a minor circulation issue.