[linnesgirl72]

We have a Goodman model number gmp100-3 and the furnace kicks on and the pilot fires on and then goes out I was thinking it may be a spider web in the orphus but I'm not sure where to find it at? If any has any information that would be helpful pleae let me know.

[hvacinmyblood]

You may be looking at a bad thermocouple(the part that says a flame is present on the pilot) If it does not detect a flame the pilot will go back out. You can try cleaning it(it's a silver looking tube about 1 1/2 inches long near the pilot) use a dollar bill and rub it. Your best bet though would be to purchase and install a new one.

[hvacinmyblood]

Just goes to show where my thinking is. Not thermocouple but flame sensor on a furnace unless it is a standing pilot that lights first. Then it would be the thermocouple.

[ivanh]

The burner assemby could be dirty also, but that condition would also cause a big "whomp soumd!" back flashing when it fires up. When was the last time you had your furnace serviced and cleaned? Very impotant! Should be done annually(unfortunately). This service is inexpensive and not a DIY, but of course you know that a house is really a big black hole on earth that sucks cash into it annually.

I have 6 furnaces in my building one for each unit. I clean them myself. But I've learned the hard way as well. Spider webs maybe, but mostly just dust, and some carbon residue is a constant menace. Cleaning usually does the trick.