So my heat is out on my TRANE XE 80 TUD080C948J1. I get 3 flashes from the LED. There is a call for heat from the thermostat. The inducer motor turns on and it spins smoothly when I turn it by hand. I replaced the pressure switch, ignitor and flame sensor. One time I saw the new ignitor light up, but only once. I don't have anything blocking the exhaust and I checked the rubber tube runnng from the pressure switch to the inducer. there are no clogs there. All this and I still get 3 flashes and no heat. what am I missing? bad board? Gas valve? Any thoughts? thank you.