Describe the maintenance required on an auxiliary boiler burner and the safety features provided on its fuel burning system?

flowchart TD
    A[Fuel oil supply] --> B[Pressure regulating valve]
    B --> C[Fuel shut-off valve]
    C --> D[Burner atomiser]
    D --> E[Combustion chamber]
    E --> F[Flame scanner]
    F --> G[Flame safeguard control]
    G -->|flame failure| C
    H[Air supply] --> E
    I[Igniter] --> E
    J[Purge air] --> E

• Burner maintenance: clean atomiser/nozzle, check flame scanner and igniter condition, verify fuel valve operation, inspect combustion chamber and uptakes for soot/corrosion, test automatic shut-offs
• Safety features: flame safeguard system with automatic fuel shut-off on flame failure, pre-purge and post-purge of furnace, air failure shut-off, low fuel pressure shut-off, high/low fuel pressure alarms, burner logic interlocks
• Key procedure: purge furnace and gas passages with air after flame failure or before lighting up; light burner at minimum firing rate; never light immediately after flame failure
• Instrument: UK MSN 1083 main §2 and §4
• EOOW action: carry out routine checks, test shut-offs, record in maintenance log, escalate defects to Chief Engineer