A reduced-pressure system (200) for delivering reduced pressure for medical purposes to a desired site and to receive fluids in one instance includes a reservoir (224) having an interior space (230) operable to contain the fluids. A reduced-pressure delivery conduit is placed in fluid communication with interior space for delivering the reduced pressure to the desired site. A source conduit (236) and a pressure sensor conduit (242) are placed in fluid communication with the interior space. A pressure sensor is placed in fluid communication with the pressure sensor conduit. A reduced-pressure source is placed in fluid communication with the source conduit. A reduced-pressure control unit (256/260) is associated with the pressure sensor and the reduce-pressure source is operable to receive pressure data from the pressure sensor and supply data from the reduced-pressure source and to determine when a reservoir full/blockage condition exists.