I started with the thermostat.
Goodman furnace does not light.
Decipher two led flashes to mean the draft blower is not working or your furnace has a short in the pressure switch circuit.
Turn the furnace off and leave the house.
Stop immediately if you smell gas.
Check your air filter if your furnace won t turn on.
If it is clogged it has not been replaced as frequently as it should have.
Find the gas supply valve next to or behind the furnace and rotate the valve to the open position typically by twisting counterclockwise.
Next i checked the on off switch.
Turn off the furnace power and repair a short or replace the pressure switch.
I then checked the junction box on the furnace.
Read three led flashes to mean your furnace has an open pressure switch circuit or it has an induced draft blower operating.
It is typically located either beside or behind your furnace if you are having a difficult time finding it.
Jumped the r and w on the thermostat nothing kicked on at the furnace.
One of the most common culprits of a furnace that is having a difficult time lighting is a low gas supply.
All you need to do is locate the gas supply valve and rotate it in a counterclockwise direction to open it.
Your furnace will not turn on if your air filter is clogged.
The goodman furnace may not be receiving an adequate gas supply if the glow ignitor turns on but the furnace cannot ignite.