Coleman TM9T problem

[how]

If a thermostat fails in such a way that it doesn't call for heat, the board doesn't read that as a fault.
If it happens again, (you wanting heat and not getting it and there isn't a fault code) then turn down your thermostat and jumper the thermostat connections on the furnace board (R & W). If the furnace fires up and stays on, then your problem will be in the thermostat or it's wiring.