[AllTemp]

During those elev years doesnt mean it was running correctly!

On the furnace commision where was the temp rise to respect to today?

As others have already mentioned limits are not continuouse duty switches. They arent made to open and close and weaken.

Temp Rise will say alot as well as system static airflow.

Once found an evaporator covered with blown in insulation that was gradually being sucked thru framing in an unpanned return chase. Return filter was clean but evap gradually restricted to the point was freezing coil in AC and tripping high head in heat mode.