Installed new goodman furnace. Blower turns on, igniter comes on, but no ignition. Gas is to the regulator, LP gas; switched jets, put silver springs in, set turns on lo-hi at 8 turns and 12 turns. Any suggestions?

Is it a honeywell, or white rodgers gas valve. Either way, the settings in the conversion instructions for how far to screw in the springs is just for getting somewhat close on pressures. I have found that many times, they are way off. You need to have a monometer to actually check and adjust the high and low pressure exactly. If they are far enough off, it will not light.

Also, and this is very important, did you fill the external trap with water? If not, the combustion air pressure switch may not close. The exhaust pressure switch will close, allowing the glow plug to ignite, but the if the other pressure switch doesn't close, it won't allow the gas valve to open. Simply dump water in the grey trap that is mounted to the side of the furnace, and see if it lites up. Im betting it will, unless of course the gas pressures are way off. Let me know. I am pretty familiar with newer Goodmans, so hopefully we can get this cleared up. Also, can you let me know the model number of the unit?

Can you post some pics of your installation, including wiring, vent and combustion air piping, and drain setup. With enough pics, I should be able to pick out any install problems, if there are any. Take care, and good luck.

White rogers valve. My gut tells me you hit the nail on the head with the drain hook up. I did NOT do that. Model GMH95/GCH95/GCH9. I do not have a monometer. Can I turn the low in to like 6, then back it out until I get a good flame? Likewise on the hi setting?

Well, judging the flame by looks is really just a guessing game, so I can't really say for sure on that one. If you are just looking to get by, I would set the dip switch on the board to 1 stage, and let it burn if its burnign with a blue flame. Actually on the white rodgers, you can pretty much screw the high side in all the way and then back it out just a half turn and that gets you really close. Low side takes some fine tuning. Did putting water in the trap make the furnace fire?