New goodman gas furnace won't stay on!!


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Old 11-14-11, 10:27 PM
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New goodman gas furnace won't stay on!!

I just purchased my home which came with a 2004 or 2005 model goodman gas furnace. It has been working fine until tonight, now the blower motor will start for aprox 2-3 secs then shuts off, repeating this every 10 secs. The LED is steady when the motor is on then goes away when it shuts off!! I have no idea what would cause this but, i need a good place to start and the damn diagnostic LED doesn't help much unfortunatly. You can hear the relay clicking on and off in-between the fan motor coming on as well.. Thanks for any help or direction


GOODMAN GAS FURNACE

MODEL# GMH80903BN
 

Last edited by Spauldini; 11-14-11 at 11:01 PM.
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Old 11-14-11, 11:27 PM
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By the "blower motor" are you talking about the small inducer motor located above the burners?

Or are you talking about the fan motor that circulates air around the dwelling?


Take the cover off the burner compartment of the furnace. Turn the thermostat up and describe in detail the sequence of events that takes place. You might need to repeat that a few times until you are sure you are observing everything that happens in the order that it's happening.
 
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Old 11-14-11, 11:49 PM
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The inducer motor is the one which is kicking on and off, here is the sequence of events..

-turn on power
-LED turns on stays steady
-inducer motor kicks on for 2-3 seconds
-motor shuts off
-a relay i believe near the circut board clicks 4 times (about 10 sec)
-LED comes back on and is steady
-inducer motor kicks on for 2-3 seconds ect.

It will just repeat this until i turn off the power. Also my gas water heater is right next to the furnace and is working just fine if that helps at all..
 
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Old 11-15-11, 01:55 AM
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If the thermostat is calling for heat, the inducer motor should turn on and stay on as long as that's the case.

Check the voltage between chassis ground (furnace sheet metal) and the W terminal on the ignition control box. When the thermostat is calling for heat that should be 24 VAC. If it is, you have a bad ignition control board that needs to be replaced.

Also check to be sure that the 24 VAC power supply to the ignition control board is staying on and is not the cause of the power shutting off.

Very likely it's a bad ignition control, but you need to do these checks to be sure.
 
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Old 11-15-11, 11:36 AM
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Originally Posted by SeattlePioneer
If the thermostat is calling for heat, the inducer motor should turn on and stay on as long as that's the case.

Check the voltage between chassis ground (furnace sheet metal) and the W terminal on the ignition control box. When the thermostat is calling for heat that should be 24 VAC. If it is, you have a bad ignition control board that needs to be replaced.

Also check to be sure that the 24 VAC power supply to the ignition control board is staying on and is not the cause of the power shutting off.

Very likely it's a bad ignition control, but you need to do these checks to be sure.
The inducer motor does come on but doesn't stay on for more than a couple seconds, should i just put a multimeter on the sheetmetal itself to test? Don't see a chassis ground anywhere..
 
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Old 11-15-11, 12:59 PM
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The sheet metal of the furnace is the chassis ground.
 
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Old 11-15-11, 02:04 PM
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Well through process of elimination we found out that the pressure switch wasn't doing it's job. I got it cleaned and now it's working good!!! Thanks for your guy's help!!
 
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Old 11-21-11, 10:14 PM
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It's definatly the pressure switch because the problem is now coming back and i have to mess with the switch to get it to fire now. I'll have to find a new one i suppose.
 
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Old 11-21-11, 11:42 PM
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It is VERY UNLIKELY that the pressure switch is the problem. The pressure switch has NOTHING TO DO with the inducer motor staying on.

The thermostat should be switching on 24 VAC to the W terminal. If that voltage is present, the inducer motor should turn on and stay on. If it doesn't you have a bad circuit board.

I suppose it's a waste of time to POST THIS AGAIN though, since you prefer your own theories.
 
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Old 11-15-14, 10:55 AM
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Same Issue.

I had same issue on my heater. Read about pressure switch on this thread. tapped on my pressure switch. and it started working. Now i am getting new pressure switch too.
 
 

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