HI, what does 5 flashes mean? Just got cold enough outside (for me) to turn the heat on for this fall. Heat comes on and off like usual but noticed the flashes. Have turned system off waited 15 minues then back on. Starts up fine but after awhile, 5 flashes start again. Any help is greatly apreciated.

Exact model number of the inside unit?

Exact model number of outside unit if heat pump?

York has made 876 different units over the years and most of them are all different and my crystal ball is in the repair shop again.

OR you can do this

Look on the back side of the blower door on the inside unit for the legend and that will answer your question if the blink is from the circuit board in the inside unit.