The purging program forces purging of the furnace, the flue gas ducts and the flue gas recirculation channel ("FGR"). In this way, any residual fuel/air mixture and/or combustion product is blown out.

To perform purging, the combustion air fan is switched on and the air duct control dampers (secondary air, primary air, cooling air) and the flue gas ducts (furnace shut-off damper, furnace pressure control damper) are opened or moved to the purge position. The purge positions and the combustion air pressure are monitored during purging. A brief interruption of the purge conditions (not a safety shut-off) results in resetting of the purge time.

The different purge sequences are shown in graphical form in the sequence diagrams.

• Flow chart: Steam Pressure Atomizer Burner (Oil Operation)

• Flow chart: Steam Pressure Atomizer Burner (Gas Operation)

• Flow chart: Rotary Cup Atomizer Burner (Oil Operation)

• Flow chart: Rotary Cup Atomizer Burner (Gas Operation)