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Goodman GMH80703ANAB - 1 Blink


gymclasshero25's Avatar
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10-12-17, 07:14 AM   #1 (permalink)  
Goodman GMH80703ANAB - 1 Blink

Blower starts, igniter turns on, but there is no flame. Tries three times and then starts the 1 blink error light. I've tried clearing the condensation hose of any clogging, I cleaned the flame sensor(even though I was pretty sure that was not the issue), and I tried tapping on the gas valve to see if maybe that was stuck and it might kick in. Thoughts?<br />
<br />
I think my next step is to pull the plug on the gas valve and put a voltmeter to it.

EDIT: I tried uploading a short video from my phone but it doesn't seem to be working....


Last edited by gymclasshero25; 10-12-17 at 07:33 AM.
 
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10-12-17, 08:20 AM   #2 (permalink)  
Trace the brown wire from the gas valve to the limit switch and see if you have voltage ( 24 vac ).

 
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10-12-17, 09:00 AM   #3 (permalink)  
error code info -https://www.manualslib.com/manual/742338/Goodman-Gmh95.html?page=42

furnace shouldn't try to light if it had anything to do with limit switch.

Do make sure there's gas to the furnace and check voltage to gas valve. voltage should be applied after igniter warmup period.

You can probably prob the connector from above, sticking the leads into the top of the molex connector.

 
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10-12-17, 09:10 AM   #4 (permalink)  
I know I have gas to the furnace.

If there is voltage coming to the valve then I have a bad valve? And if there is no voltage coming to the valve then something is wrong in the wiring or the board? Is that correct?

 
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10-12-17, 10:16 AM   #5 (permalink)  
Welcome to the forums.

You cannot load a video here. It needs to be hosted at a site like youtube and linked here.

Yes...you are correct.
You need to check power to the valve with it connected.


~ Pete ~

 
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10-19-17, 04:40 PM   #6 (permalink)  
Getting one blink on my Goodman furnace. Igniter turns on but no gas comes out, tries to fire three times and then starts the one blink error light.

I tested for voltage to the valve and there was good voltage coming when the igniter turned on. So I figured I had a bad valve. I just bought and installed a new valve and I have the same problem.

Any thoughts on what might be wrong and what I might check next?

 
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10-19-17, 04:45 PM   #7 (permalink)  
Your original thread was there. Joined two threads.

There should be no voltage to the gas valve until just before ignition. Usually the igniter needs to heat up for 15-45 seconds..... you'll hear a click.... the gas valve gets power..... if no ignition in approx 7 seconds the igniter will shut off and power will be removed from the valve.


~ Pete ~

 
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10-19-17, 04:50 PM   #8 (permalink)  
I can definitely hear the click after the igniter has been on for about 15 seconds but no gas comes out so the igniter shuts off.

 
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10-19-17, 04:56 PM   #9 (permalink)  
In the link below is the wiring diagram. An aux safety is shown in the brown wire to the gas valve. For ignition you need 24v power on that line and the C terminal is the blue wire.

hvac/media/manuals/specification/GOODMANGMH8.pdf


~ Pete ~

 
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10-19-17, 05:30 PM   #10 (permalink)  
Did you follow skaggsje's checks? That furnace has a two stage gas valve so three wires: common, medium, and high. Verify you have voltage between common and medium as well as common and high for ignition. If no power on medium then check the limit aux switch switch mounted to the blower cage.

 
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10-19-17, 06:28 PM   #11 (permalink)  
I followed the brown wires and there is power going to the limit switch.

 
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10-19-17, 08:02 PM   #12 (permalink)  
That brown wire is only one half of the circuit. You need to check for voltage on both sides of the switch to Common or ground. The blue wire on the valve is C.


~ Pete ~

 
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10-19-17, 08:06 PM   #13 (permalink)  
To me it looks like two brown wires and a blue wire come off the valve.

 
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10-19-17, 08:19 PM   #14 (permalink)  
I can only go by the manual. It shows.....
1 - PM - brown and goes to the limit switch.
2 - HI - white and goes to pin 12 on the 12 pin plug.
3 - C - blue and goes to pin 9 on the 12 pin plug.

By the way... remove that 12 pin plug from the board several times as those pins can become corroded. A little contact cleaner on the pins is helpful too.


~ Pete ~

 
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10-20-17, 08:45 AM   #15 (permalink)  
There is definitely not a white wire. I'll try to figure out which one of the brown wires goes to the 12 pin plug.

When I tested the valve connector for voltage, there was voltage when I probed the C and the HI (I believe). Should there be voltage coming when I probe the C and the PM also?

 
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10-20-17, 06:29 PM   #16 (permalink)  
There should only be power when the burner is told to light.
There cannot be always live power as the gas valve would stay open.


~ Pete ~

 
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Today, 08:54 AM   #17 (permalink)  
There is only voltage when it is told to light.

My question: It's only when I probe the C and the HI on the connector that there is voltage. There is no power when I probe the C and the M. Should there be power/voltage there also?

 
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Today, 04:20 PM   #18 (permalink)  
I started working on the furnace after work tonight. I'm not sure what I did but it actually started working.

But now its doing this: https://youtu.be/YtlInritPhE

You can see at about the 30 second mark it starts 'sputtering' and then it goes out. I can hear a clicking while it's doing that. Any ideas what might cause this issue?

EDIT: I can feel it's the valve that's clicking when I put my hand on it. Could I have gotten a bad valve?


Last edited by gymclasshero25; Today at 04:49 PM.
 
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Today, 07:11 PM   #19 (permalink)  
Appears to be chattering the pressure switch, or momentarily loosing flame signal.
Check the pressure switch while running, and check flame feedback from the flame sensor.

 
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Today, 07:53 PM   #20 (permalink)  
There is low voltage to the pressure switch while running. What do you mean by check the flame feedback?


Also, if I turn the furnace off and let it sit for awhile, it will run perfect for about five minutes or so until it flames out. Once it flames out it starts happening every time within about 20-30 seconds. But it doesn't seem to error out, it just keeps lighting and then flaming out.

 
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Today, 08:00 PM   #21 (permalink)  
Check mA feedback from the flame rod with your meter.
It's starting to sound like some sort of heat exchanger issue.

 
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Today, 08:09 PM   #22 (permalink)  
It's not a flame sensor problem. If it was..... the board would go into complete and immediate shutdown. It won't allow the board to chatter.

You have either an intermittent connection or a dirty relay on the control board or your front pressure switch is on the edge and opening. . Did you remove the 12 pin plug several times ? You need to monitor voltages to the gas valve and see which one is changing.


~ Pete ~

 
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Today, 08:34 PM   #23 (permalink)  
I did remove the 12 pin plug a couple times. The voltage changes on the "HI" connection to the valve, but does not change on the "PM" connection.

 
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Today, 10:26 PM   #24 (permalink)  
Ok. Try this..... with the burner running..... tap on the control board with the handle of a screwdriver. See if that increases or affects the problem. If it does.... it's a board problem. Most likely a dirty relay.


~ Pete ~

 
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