Treadmill is an expensive exercise equipment costing thousands of dollars. It has mobile parts that can get damaged. Hence taking good care of the equipment is very essential. Bad maintenance can cause more damage than repair. Refer to the manual supplied by the manufacturer for proper maintenance tips.
The first important thing to do for the maintenance is dusting it all over every week. Dust affects the smooth functioning of the conveyor belt. You should ensure proper dusting in the areas below the belt to remove any dust that has gathered below it.
There are many types of treadmill maintenance kits sold in the market. They use silicone. Once you have through dusting and if recommended by manufacturer, use the kit on the mobile parts. Just pour few drops of lubricating fluid through the dropper on these parts to minimize the friction. Use the liquid according to machine type, because wrong choice of liquid can make the belt slippery leading to loss of grip, besides bringing on the host of problems. Buy the maintenance kit directly from the manufacturer. You can also derive the same benefits from a non-abrasive, non-acidic cleaner fluid.
Do not wax the deck unless recommended by the manufacturer. Most of the manufacturers have coated the belt for better grip. Waxing will only destroy the coating, causing it to lose grip.
You should take of other minor things like cleaning the console and handrails with a damp cloth, ensuring deck is clean. Keep wetness away from console. Get proper grounding to avoid the crashing of digital parts.
Over a period of time, the movement of treadmill slows down. The belt may align to one side or loosen and start sagging. In all these cases, bring the belt back to center. Do not make the belt very tight.
When the level of treadmill and floor becomes uneven, it can squeak when the belt is moving. Bring the treadmill back to the horizontal level.
You can follow these procedures by yourself, instead of hiring the professionals to do the work. This will save your money considerably. But do not try to do complicated procedures like changing the blown fuse or replacing the damaged part yourself. It is better to contact a professional.