[Justin002]

My Goodman GMPN060-3 Rev A tries to start up and hums for about 4 minutes and stops. There is a solid red light. I've reset it and turned everything on and off I can see. I came home around 7 and have been tinkering w/ it. Nothing seems to get it to go. Anyone outhere that can help at this time would be much appreciated.

Thanks.

[T-Top]

This is a condensing furnace(makes water when it heats) You can have a froze or restricted drain line going to the outside tripping the pressure switch. You should have a flashing light on the control board letting you know what's wrong.

[hvac1000]

http://www.alltemp-hvac.com/gmpn.pdf

Your manual.

What is humming?

[Justin002]

Thanks guys, but just gave up for tonight and just took the family to a hotel. Just checked in @ the Super 8 in town. Free WiFi. Anyway, will try to tinker with it tomorrow. Thanks again. The light on the unit was solid red. The humming sounds normal , maybe used the wrong word. It sounds like it's going to start like normal but fails after a few minutes. I tested the fan on fan only and also tested the AC unit. It seems to work fine in both instances; however, just the heating it tries to kick on but fails to ignite and the fan does not start on the heat mode. Thanks again.

[Justin Orr]

Well the fan not starting in heat mode is a problem because it runs before the ignitor ignites the burner. It needs to blow the stagnant air out before the burners ignite as an added safety precaution. If the fan doesn't turn on at first, the vent pressure switch won't close, and the heat circuit won't energize at all. So why won't the fan turn on? Its got to be a low voltage problem within the heat circuit because it operates when you turn on "fan on". My guess is it could be either the power vent relay or the fan blower relay 2. when you hear this humming, does any air blow out of your vents? Do you feel any warmth at all? There are many safety switches that can trip for many reasons, so my guess is its one of those. The problem is finding which one. If it's the fan blower relay number 2 (referring to the schematics in the manual that hvac1000 provided, last page) then the humming could be the first fan used to purge the ductwork. Then the burners ignite and when the first fan shuts off and the blower fan is supposed to take over, it doesn't, causing safety switches to open up and extinguish the flame before anything can start. Just a theory.