If it doesn't, adjust the tension. Carefully clean and oil the blower motor. Clean the blower fan monthly to remove dust accumulations from the blades and motor body. Check to make sure that the door to the blower cabinet is closed. Make sure the power to the motor is off when you clean it.
Vacuum register grilles and gently clean the thermostat.
Remove grilles and check for obstructions in all ducts and in the cold air returns. Tape seams in ducts and check to make sure that all ducts are connected. Your qualified furnace contractor or service provider should include these steps in the inspection and cleaning of your furnace. An oil furnace should be inspected and cleaned yearly and a gas furnace should be tuned-up every other year. Perform a test for carbon monoxide.