Customer advised that sense the recent tuneup there new system has failed to come back on. System was already turned on at stat and no air blowing out of the vents. Furnace was showing that it was locked out. Reset power to system and restarted. System ignited and began heating the house Problem was caused at the end of the tuneup and testing of equipment, on the variable speed system while conducting routine maintenance the door safety is bypassed. If you release the door safety before the system shuts down on its own, or blower speed slows, the sudden stoppage of equipment will cause a limit to trip. Recreated the same issue multiple times while testing this system System will not restart until the limit is reset. Previous tech would not have known this however needs verified that the system is operational when tuneup is completed.
