The last few days I've noticed that the Vent Fan (not the ID Blower) for some strange reason starts and continues to run although the stat switch is in the Off position. When I turn the power off momentarily, the fan will stop but after several minutes it will start again. When I call for heat, the sequence of operation starts normally but after the set point is met, the burner and the main blower will shut off but the vent fan will continue to run. I suspect that there is something wrong with the Integrated Furnace Control. Am I on the right track?