Abstract: A sootblower is provided for cleaning boiler tubes with steam, in which individual time-delays allow the lance tube to move in an axial direction only for certain time intervals at the beginning of the extension and retraction strokes before the lance tube also begins to rotate. The sootblower can operate in a reverse cleaning mode in which the nozzle at the end of the lance tube continuously rotates in one direction during the entire extension stroke, then reverses its direction of rotation for the entire retraction stroke so that the paths of steam cleaning do not criss-cross during any given extension/retraction stroke. In a second embodiment of the sootblower, the nozzle on the lance tube oscillates between pre-determined minimum and maximum arcuate limits about the rotational axis of the lance tube.