My Goodsman furnace is not coming on. My pilot light is on and I tested my thermostat and it working. I changed my filter, changed my SSU fuse and made sure that the doors were closed. I don't see a switch to manual turn it on. I don't know what else to do could someone please help me. It is starting to get cold.

Did you check to see if the gas valve is in the on position after lighting the pilot.

It should be I have not touched any thing from last year.

Did you check for low votage power coming from the stat telling the gas valve to open?
Is there low voltage from the transformer to the stat?