I have a 80% Carrier furnace! I have to shut off the power some times for it to start up again! Then I have to turn the thermostat way up for it to go!!
Do I have a bad stat or do I need to replace the ignighter and or the glow plug?

If you have a flame sensor clean it first and see if that takes care of it.

`If you have to unplug it ,that tells me it is going into lockout, before you unplug the furnace check the number of flashes and look on the furnace door for the corresponding problem. Mike