How to adjust my comb. Air on my gas furnace? Flame's yellow and can't find shutter.

Extension of my question. (don't give you enough room) When my furnace is cold, the gas won't always ignite and when it does the flames got some yellow in it. Goodman GPD model - I can't locate the shutters to adjust the air. Does this model even have them?

I don't think that furnace has a way to adjust the air flow. It may be that you have low gas pressure. Or it could be that the burners are dirty, use something hard and tap the burners as they are burning and see if it makes a difference.

Proper tools are needed to adjust the gas pressure unless you want higher utility bills. The days of eye balling the flame to adjust is over. Then after the gas pressure is adjusted you need to take a combustion efficiency test to make sure all else is performing correctly. Here again without the proper tools a lot of energy is wasted.

I assumed that the gas company would do the adjusting of the gas pressure, they do in my area and it is a free service.