Abstract: A soot blowing system for cleaning banks or clusters of heat exchange tubes or the like contained in a furnace or flue housing comprising a movable platform carrying an apertured lance which is inserted sequentially into spaced openings in the wall of the furnace or flue housing so as to pass in proximity to the banks of the heat exchange tubes; the lance is directly connected to a flexible steam supply hose and is incrementally rotatable over a pre-determined area within the furnace or flue housing to steam clean the tubes in that area; upon withdrawal from the housing the platform and lance move to the next aperture in the housing where it is inserted and again incrementally rotated to clean that area of the tube bank.