Woke up to a freezing cold house. I started my troubleshooting at the thermostat. All seemed good. Pulled the cover off the main unit, but no codes had been thrown. Prompted it to fire up. Thermacouple glowed good and hot, flame fired, then out after a few seconds. Try again, same result. Huh, reminds me of the furnance in our last house, which is where I learned that pulling the flame sensor and cleaning it with a dollar bill is a potential remedy for not maintaining flame. So, I pulled it and rubbed it down with Washington's face and BAM! Flame.
Wanted to pass along my new HVAC troubleshooting knowledge in hopes it helps someone else!