Started having problems this winter furnace will blow cold air .looked at filter changed it cleaned flame sensor. Led flashes 5 times states it's a roll out. When we turn main power off to furnace and then turn back on furnace cycles normal and blow heat. Is it possible that roll out switch is bad and I have read there are three for this furnace. It's a luxaire model PBKM LO12NO8OE installed in 1996

Most roll out switches have to be manually reset by pushing a button in between the wire terminals. If your furnace is working at all without resetting the roll out, you either have a bad roll out, or the board is giving an inaccurate code, in which case you have a bad board. There is a possability that some one has replaced the rollout switch with a limit switch that resets itself once it cools off ( a big no no).. I would suggest getting a tech in to check the system ASAP.