Fan limit switch was tripping when heat would kick on -I took apart the switch and inspected it and it was extremely dirty underneath it -I put the switch back in and the heater is running properly now -I shut the unit on and off multiple times it is starting up properly -Our client is aware that if it does happen again, that it is an issue with the limit switch or the blower motor is not sending enough air throughout the system, causing it to go out on high limit