Following precautions shall be taken to prevent Boiler furnace blow back -

• Allow sufficient time for pre purging the furnace with dampers full open to ensure all the accumulated vapors are expelled out.
• Purging to be carried out 5-6 times the furnace volume for effective expelling.
• Never try to reduce purging time or bypass it.
• Carry out boiler burner and swirler routine as per planned maintenance system.
• Do not fire boiler with heavy fuel oil or sludge if it is not designed for the same.
• Air fuel ratio of oil compound regulator to be adjusted correctly to maintain proper and complete combustion.
• Pilot burner to be maintained in good condition so that flame failure while starting does not occur.
• Igniter or ignition transformer, its leads, etc. to be properly insulated and tightened.
• Fuel oil fed to the boiler to be properly treated as per manufacturer’s recommendations.
• If an economizer or pre heater is fitted in the boiler exhaust, same to be water washed and inspected regularly to avoid back pressure of gases.
• Conduct furnace inspections periodically to inspect conditions inside.
• When a flame failure is experienced find and rectify the root cause. Do not try to fire again and again.