Hi,

I'm trying to understand how I can fix a Goodman GMPN Condensing Gas Furnace.

Problem:

Heating Mode - I start the heating phase by selecting higher temperature on the thermostat to get the furnace in heater mode. There is a small fan that starts for about 30sec then everything just stops. I don't see the gas or blower doing anything. I've check all the connections and doesn't seem to have any wiring issues. I don't smell gas or hear gas coming out of the burner. Any clues to what next? Most appreciated.. . :confused:

Could be several things. Could have a blocked flue, a stuck or failed pressure switch etc etc.

Unit should have a fault indicator LED viewable through a clear plug in the blower access panel. You may have to look closely to see it as there will probably be some wires obscuring your view. A label on the inside of the panel will tell you what the flashing codes mean.

Unit should have a fault indicator LED viewable through a clear plug in the blower access panel. You may have to look closely to see it as there will probably be some wires obscuring your view. A label on the inside of the panel will tell you what the flashing codes mean.

Ok, I checked the LED flashing 3 times indicating Pressure Sensor/Switch fails to close. I checked and cleaned out the rubber hose connecting the Pressure Switch and connecting to exhaust fan. It's all good, no blockage and made sure its tight. However, the LED continues to flash 3 times indicating Pressure Switch fails to close. Any ideas before I drop $300 for a furnace service technician? Much appreciated.