Hi, and thanks for sharing your experience with the Traeger Timberline. Even though the basic functionality of most pellet grills is the same, there are a few things to get used to when going from the original style Traeger to something as new and advanced as the Timberline. While maintenance is certainly the single most common cause of grill fires on any type of outdoor grill, this doesn’t appear to be the case in your situation. With this eliminated, there’s only a few other possible reasons that fires might occur. One of them is putting aluminum foil or a liner on the drip tray. Due to the way that the new EZ Clean trays are designed, they do not require any kind of protective covering, while still being very easy to maintain, and using one can certainly result in a grill overheating, or on rare occasions, a grill fire. Another possibility is that the firepot is not completely seated at the bottom of the grill, with the right lip caught on the lower edge of the auger tube. This may cause the pellets to collect beneath the pot, where they can eventually ignite, creating more heat than expected. Additionally, if the grill did not go through the full shutdown on a previous cook, there could be excess pellets remaining in the firepot for the next run, creating a larger fire than usual. But as opposed to trying to work this out by yourself, please give Traeger Customer Service a call for assistance. One of our agents can check over everything with you, and maybe do a test run as well, likely having the grill working perfectly by the time you get off the phone.