I found another problem that helps, but the insulation still touches the cover. The air filter element was incorrect. I had a 4 bbl element, 3" high, that didn't sit in the bottom of the unit so the cover was not down tight, about a half inch too high. The 2 bbl air filter is 8" in diameter and 2.5" high and sits in the upper part of the cleaner. The cover is touching the lower part of the cleaner and the top of the filter.