A controller (170) for managing reduced pressure, supplied by a reduced pressure source (110) to a tissue site (105), and measured by a single pressure sensor (155), the controller (170) configured to: detect a change to an operating parameter of the reduced pressure source (110) indicative of a change to reduced pressure generated by the reduced pressure source (110); determine an actual reduced pressure at the tissue site (105) using the single pressure sensor (155); determine a responsiveness of the actual reduced pressure measured by the single pressure sensor (155) to a change in reduced pressure generated by the operating parameter; and emit a signal using an indicator (180) in response the actual reduced pressure at the tissue site (105) being nonresponsive to the change in reduced pressure generated by the reduced pressure source (110).