According to Hoover, the five most common types of issues that arise for wind tunnel vacuum machines are changing the bag, belt, bulb or filter, cleaning the easily cleaned filter, cleaning the washable filter, and bag replacement. Unplug the wind tunnel before performing any maintenance on the vacuum to limit any electric shock.
To determine which problem exists, start by replacing each item -- the bag, belt, bulb and filter -- one by one. First, replace the bag. If the problem still exists, replace the belt. If the problem persists, then replace the bulb. If the problem still persists, replace the filter. If no replacement parts fixed the problem, move on to cleaning. First, clean the reusable filter. If that does not fix the problem, then clean the washable filter. If that still does not fix the problem, check the belt for debris. Once any debris is cleared, the last step is to contact Hoover customer support and consider sending the vacuum in to be looked at by a professional. Usually, replacing a part of the wind tunnel vacuum fixes the problem, but occasionally, the problem is electrical or exists within the machine itself and simply replacing items does not fix the problem.