I have a fairly new trane XB90 system that works mostly but often it does not turn on ... BUT when I cycle the power on/off it does and works for several hours and stops again
(natural gas furnace, forced air, airconditioner) - I can hear the blower turn on/off - as if waiting for something but the gas does not come on)

I need to keep the power off for atleast 10 minutes or so and then it turns on ... and the heat is great (it did it again this morning and it is not turning on now ... setting 74, temperature 70)

The repair guy said something about the board - BUT this is a almost new system - 1 year old or so ...

What else could be going on?

thanks all