The two service men arrived first thing in the morning (7:45 AM) as promised. They made a very thorough examination of the control systems on the furnace to insure everything was functioning properly. The call was in response to an incident where the hot air blower did not start when the burner started and had reached the correct temperature for the blower. Because this had occurred on Sunday evening, I tried shutting off the furnace and restarting it. Everything then began working properly. My concern was that there was something wrong with the controls and could happen again very soon. They assured me they could find nothing wrong. They asked that I not restart the furnace if this happens again but call them immediately.