Specs: Goodman Model GDS80703, over 10 years old, Control board replaced 2 years ago

2 months ago, it just started glowing and not igniting, and after doing some basic troubleshooting (Reboot, clean filters, reset thermostat) the problem wasn't solved

As there was sufficient voltage to the gas valve, I was advised by a tech over the phone to replace the gas valve, and did so, It fired up about three times, and each time it didn't reach the temperature desired

Now, we're back at square one, and so we come to you, the people of the internet, for help.