I have a Goodman GMP Series gas split unit furnace that I had installed approx 12 years ago. I have had no problems at all until this week and there is no heat. Someone at the gas company said that it may be the glow plug. It does not light up at all when the furnace kicks on. I have called several heating and air people but with no one calling me back it is time to take matters in my own hands. Is this part easy to replace? It looks like just a screw holds it in. I have the repair parts booklet and the installlation manuals from my installer (who is no longer in this area). I do not see something listed as a "glow plug" so what is the correct name of the part I am looking for.
Thanks for any help.

Igniter

It may be listed as a "Hot surface ignitor" it will look like it is made of carbon, it is a dark gray and it will have two electrical leads going to it. If you find it a good way to check it is to disconnect the wires at the little pull apart connection. Then use a volt meter to see if you get 120 volts when it is time in the cycle for it to come on. Also look at it and see if you see a crack or maybe a spot that looks like it is a little white, if you see them that means it is bad.

On installing a new one be very carful because it is very brittle and do no touch the gray part with your fingers the oil in your fingers is not good for it.

If this helps let me know.

Letmetellu's advice is right on and I might add that the Goodman furnace is notorious for getting the orifice on the induced draft blower housing plugged up , this has the small tube attached to it, just stick a small wire or drill bit through it to make sure it clear, good luck, Mike