--- The inlet vane damper of ID and PA should be closed.
--- The secondary air damper and the combustion air damper should be set at the position of “manual”, and they should be closed.
--- The control system of ID and PA should be set at the position of “manual”.
--- Start the induced draft fan (the inlet vane should be shut off firstly).
--- The furnace pressure should be automatically controlled.
--- Start the primary air fan (PA).
--- The back-feeding air fan should put into use, and the air damper should be opened.
--- Check the air flow in the back-feeding box.
--- Start the secondary air fan (SA).
--- Open the inlet vane of the blower and induced draft fan slowly, and check the furnace pressure.
--- Adjust the blower and the induced draft fan, and they should be manual controlled.