Traeger Grills are designed to circulate smoke effectively without causing ash residue on your food, so finding ash on your food, though uncommon, is not impossible. Having this symptom typically boils down to an airflow/circulation issue.
First and foremost, is your grill clean? At the very least, you should be cleaning out your grill every 20 hours of cook time. For additional information on proper maintenance and cleaning, see Grill maintenance.
If your grill has a chimney cap, ensure that it is not screwed all the way down. You should be able to fit your thumb in between the cap and the chimney.
If the fan sounds faint, turn off the grill and try to spin it manually. This will help loosen up dirt or grime that may be preventing it from running at peak efficiency.
Make sure the firepot, drip tray, and heat baffle are all undamaged and installed correctly.
For a Traeger to have the proper air circulation, there needs to be at least an inch of clearance on each side of the pan. If the pan is too big it will change the air circulation which can cause ash to get on the food as well as temperature issues.
If you still continue to have issues, please contact Customer Service at 1-800-TRAEGER.