There is a clean out port on the back on the lower portion. Remove two screws to remove the cover to gain access to the air path from the floor to the bag. If this doesn't solve it you may have to remove the screws on the bottom which allow you to remove the cover of the nozzle assembly. There is a cover that goes from the floor to the direct air motor. Remove the screws to remove this cover which gains access to the air path and fan of the direct air motor. It's possible you may need to remove the direct air motor to clean out the fan if it has something stuck in there. This is not a job for the average person but if you are very mechanical you should be able to do it. If in doubt take it to your dealer. It is not very expensive to have done.