Fluid is circulated through a heat exchange system for heat exchange to occur at a bundle of tubes making up a portion of the heat exchange system. Heat exchange efficiency at the bundle of tubes requires debris and fouling deposits accumulated therewithin to be substantially removed. Taking the heat exchange system off-line for physical flushing is not only ineffective but also disallow use of the heat exchange system for the duration it remains off-line. Described herein is an embodiment of a cleaning system which uses a displacement system for displacing cleaning balls carried in fluid into the bundle of tubes for cleaning thereof. A flow diverting system is configured and operable for introducing the cleaning balls to the bundle of tubes when in a first operating mode and for retrieving the cleaning balls from the plurality of tubes when in a second operating mode.