A patient support apparatus pneumatic system may include a mattress defining an interior and a pneumatic enclosure in fluid communication with the interior and comprising an inlet and an outlet. A blower may be in fluid communication with the interior and the pneumatic enclosure. A pressure sensor may be configured to detect a pressure at the outlet. A controller may be configured to monitor a speed of the blower and the pressure at the outlet for detecting at least one of an intake blockage condition and an exhaust blockage condition.