My Hill-Rom® Wound Surface 300 keeps alarming low pressure, how do I address this issue?

My Hill-Rom® Wound Surface 300 keeps alarming low pressure, how do I address this issue?
 

First, check the CPR valve to make sure the plugs are pushed in all the way. For models with the turn valve, make sure it is in the closed position. If the problem persists, call 800-445-3720 .