Treadmills require the most servicing of any type of fitness equipment.  The frequency of maintenance varies by the manufacturer.  Labor entails vacuuming, calibrating, cleaning, & lubrication (wax or silicone) as per manufacturer's specifications. We test the running and drive belt to ensure proper tension as this is a frequent service problem.  Other frequent problems that may occur deal with leveling the machinery, broken front and rear rollers, end caps, and electronic malfunction of speed and/or elevation.  Regular maintenance increases the probability that your treadmill will last the distance of your investment.