Your boiler has stopped running as a safety precaution because it couldn't successfully light or maintain a flame.

Technical description

The burner control box lockout safety feature operates automatically if a fault occurs in the burner operation. This could be caused by: an interruption in the fuel supply, an electrical supply fault, a fault with the burner or its safety control system, the failure of a burner component, worn or dirty oil nozzle, or incorrect flue installation.