Check your electrical connection, if your Hoover Central Vac isn't running at all. Make sure the power cable is firmly plugged into a wall outlet. Check the circuit breaker to ensure it's in the "On" position.
Empty the attached Hoover Central Vac dirt container, if your Hoover Central Vac suddenly begins to have a difficult time sucking up dirt or dust. A full dirt container reduces the appliance's suction. When replacing it, make sure the dirt bucket is positioned properly and that it is clamped tight.
Clean or replace the filter if the vacuum continues to have difficulties. Check to make sure nothing is obstructing the cleaning hose or nozzle, as this can also cause suction problems with the device.