The same thing happened to me. I had that issue while cooking low (250°) and long (5 hours or more). I talked to a craftsman from https://firerecruitmentaustralia.com.au , and he told me that I should clean it more often or every time I use it. His advice was to take everything out of the grill and start it up. Once the start-up process is done, increase the temp to 250, then close the lid until it reached temp. Then, open the lid and keep an eye on what it is doing to see if the drill keeps filling the pot and not stopping. That's it.