Sue Vang inspected our unit 2 different times when the furnace stopped running and restarted on its own. Found nothing he could fix. After first call he stated if it happens again don't try to start it and call immediately. It stopped a second time and we called at 8 AM for service as told. The heater re-started at 11:30 by itself. Sue Vang showed up at 12:30 after we were given a 8-11 window of arrival. He performed the same tests and could not determine a cause. He left without a suggestion or opinion as to what to do next. He noted in his writeup that it has to fail completely before it can be detected. That does not help us at all. If your company could get out to us when it is off it would make a big difference in fixing the problem.