I have a pretty new 440D2 and it keeps going out at low temps like 225 and 250. I started a 14 hour smoke at 3 am and ran great till about 8am before a flame out. I think the direct sunlight when the sun came up had something to do with it. I put it in the shade then it ran again for quite a long time like 3 hours and then went out again. Now it is unpredictable. Another time, 15 mins before it went out. I have to babysit this thing now. I am starting to mess with P settings but forums are telling me it only works for the smoke setting and others say different it is across the whole range. Others say p-mode works up till 250. I can always hear a fan, but there seems to be some secondary fan, like a jet like forced air fan that kicks in and out. When it kicks in, I know I am good. Other wise High temps seems ok. fluctuates + or - 50 degrees at high temp, but at least it doesn't go out. But then again high temp cooking never lasts any more then an hour. I started it clean with no pellets or ash in the pot either.