Blowback from boiler furnace is a very dangerous situation where the hydrocarbon mixture in the furnace catches fire which may lead explosion
It occurs when lighting up with explosive gas and oil droplets ( oil residue) inside the furnace without preparing sufficiently. The ignition results in a large flue gas inside the furnace and these gases blow out with high pressure through the furnace openings.
Action in case of Blowback
> Stop boiler start purging
> Open the burner door and check for fuel accumulation within the furnace to check nozzle tripping
> Check the condition of no nozzle
> If all checks are satisfactory shut the burner door
> Start the burner sequence with pre purging
> If the burner backfires, do the troubleshooting before starting the boiler again.