I found this same thing on a new AAON too. In fact my partner just worked 80 hours redoing some controls on a bunch of new AAONs that we get to back bill the manufacter for-all approved by them. Nice looking units but I wonder about the people at the plant where they make em. Also want to know where they buy the OEM filters or where the guy that makes the filter racks lives. Have had to redo more then a few so I could get filters in. Had one vortex fan suck up a filter and shake itself apart because some one smashed filter to get it in and someone tightened the spring mounts all the way down or never checked em after install.