Many times when a central vacuum hose is clogged the owner will assume that the entire system is plugged. However, that is most often not the case. If you are experiencing suction problems with your central vacuum system, you should check the hose for clogs before making the call to have a repairman come out.
Step 1 - Reverse the Flow
First of all, plug the hose into the inlet in reverse and turn the system on. The clog should move enough to slightly unclog it.
Step 2 - Force the Clog
Next, unhook the hose and push a broom handle through it. Since the broom handle is not long enough to reach through the entire hose, accordion the hose toward you. This will allow you to get the entire hose wrapped around the broom handle.
Step 3 - Run a Snake
If none of this works and you have access to a plumbers snake, run one through the hose. This will definitely dislodge any clog in the hose.