Upon arrival turned system on. Indoor unit came on. All zones where operating properly. Went outside, outdoor unit came on and stayed running for 45 mins. Slowly dropped zones off 1 by 1 and turned them back on and zones are all showing ok. Let system run awhile and pressures, and all electrical is working ok at this time. Without it failing in front of me I can not be sure of why the system is shutting down. I can recommend with age the stat and dampers maybe failing. Spoke with customer about it and spoke with Ryan about it and he agreed. If it fails again I am going to recommend looking at a new stat and dampers.