Good idea, maybe the door is letting air in. The ash box doesn't seem to have a good seal on it either.I don't have the 430. Setting 1 is for chips and 2-5 for chunks. The chip/chunk door can be leaky so some have adjusted/altered the latch to get a tighter fit or you may have to make a gasket out of high temp RTV silicone in the automotive section of a big box store or auto parts store. Opening the smoker quickly can stoke a lot of chips to flame up with a leaky chip door. Count out ten chips with setting 1 and see how that smokes and how long.