Just finished my 2nd cook on a new to me 22" kettle. When I shut it down the coals continue to burn, staying hot or warm for at least a couple hours, pretty much till the coals are shot. When cleaning it up earlier this week I noticed one of the sweepers does not ride right on the kettles base, it's about an 1/8th" up, is this enough to keep the unit from going out or is this normal for a 22? I can order replacement sweepers if it'll help. The lid vent seems fine.