# Goodman 6 flashes fails to light after fan



## barnis (Feb 10, 2011)

I have a 2-year-old goodman 95% furnace with non-variable fan. I'm not sure of the model number. It worked fine last year and never gave us any issues. This year it began acting up on Christmas. I would hear the fan cycling with no heat. I checked and it was flashing 8 times. 

I called the guy who installed and he came out and said it was a bad ignitor which he replaced. It was then OK for about 2 weeks and the same issue started again. The termo calls for heat, the unit cycles on and fan starts, I never hear gas flow and after about 20 seconds it shuts off. It repeats every 5 minutes or so and sometimes eventually lights. If I power the unit off and immediately try again it again fails to light. If I power off and wait ~30 minutes it lights fine and generally continues to cycle OK for about 12 hours or so. 

I called a 2nd tech to look at it and he immediately suspected water in the vent lines. There was none. He then cl;eaned and check and said his suspicion was a) goodman sucks b) the unit was not getting sufficient air c) the unit is over-sized for out home/ducting d) the flame was turned too high. He adjusted the flame lower and told us to keep all registers open.

The unit then worked without issue for another 2 weeks or so and has now started it's issue again.

We power off for ~30 minutes and then it works for 12 hours or so.

Here's a few suspects that I have:

1) gas pressure is low (I don't believe either tech checked this) and the unit seems to work worse when we use a lot of hot water (gas water)

2) The vent lines are clogged. (I haven't checked yet due to snow/mud)

3) The circuitry is bad

4) The unit is truly over-sized for the house/ducting

Any help would be MUCH appreciated!!


----------



## plummen (Jan 10, 2010)

which blower is coming on,inducer motor or fan on bottem of furnace?
1-stat calls for heat
2-inducer motor begins to spin creating vacuam which closes pressure switch next to inducer motor.
3-pressure switch sends signal to board which in turn heats hot surface igniter.
4-once igniter lights/heats up gas valve opens to light burners
5-flame sensor(thermo couple replacement)senses flame and keeps burners lit,if no flame is detected shuts down gas valve
6-once furnace reaches temp blower motor comes on to circulate air through house.
are these things taking place,which one does it stop at?
how are the combustion/flue pipes attached to furnace?
can you remove flue pipes from top of furnace and try to operate it shortly?(open doors/windows while doing this) if furnace runs,check flue pipe and combustion air pipe.
what size of gas line is feeding your furnace and dryer?
most furnace warranty issues are caused more by install issues than anything to do with a brand name in my experiance anyway.
got any pictures of install?


----------



## HAMP (Feb 9, 2011)

plummen said:


> which blower is coming on,inducer motor or fan on bottem of furnace?
> 1-stat calls for heat
> 2-inducer motor begins to spin creating vacuam which closes pressure switch next to inducer motor.
> 3-pressure switch sends signal to board which in turn heats hot surface igniter.
> ...


I have a thread with close to the same problem:
http://www.diychatroom.com/f17/heater-will-not-stay-95043/

with mine it's #5 on your list, except a flame starts, but it still shuts down. It never reaches the desired temp to blow thru the house


----------



## plummen (Jan 10, 2010)

if lame comes on but doesnt stay lit id pull the flame sensor out(usually just one screw to remove) be carefull removing the wire if you need to remove it.
if flame sensor has any white/black crud on it clean it with fine steel wool and reinstall. :thumbsup:


----------



## barnis (Feb 10, 2011)

*let me see if i can answer...*



plummen said:


> which blower is coming on,inducer motor or fan on bottem of furnace?
> 1-stat calls for heat
> 2-inducer motor begins to spin creating vacuum which closes pressure switch next to inducer motor.
> 3-pressure switch sends signal to board which in turn heats hot surface igniter.
> ...


It stops after step 3 and then flashes 6 times in the lower window LED.
After a power rest (~30 minutes) It run as normal and brings the house to the requested heat.



> how are the combustion/flue pipes attached to furnace?


The flue pipes are attached to the top of the furnace one is stepped down from 4 inch to 2 inch at the furnace. the other is also stepped but has a small rubber section to allow some give. Presumably because the install was not perfect and the pipe wouldn't reach perfectly.



> can you remove flue pipes from top of furnace and try to operate it shortly?


It operates fine after a reset so I believe the flues are OK?


> what size of gas line is feeding your furnace and dryer?


Gas line is 1 1/4" to house and the stepped down prior to water heater and furnace to 1"


> most furnace warranty issues are caused more by install issues than anything to do with a brand name in my experiance anyway.


I would assume so too...the ignitor was replaced and that didnt help so most likely install issue?



> got any pictures of install?


pictures here
http://imgur.com/a/J6NrG


----------



## barnis (Feb 10, 2011)

plummen said:


> if lame comes on but doesnt stay lit id pull the flame sensor out(usually just one screw to remove) be carefull removing the wire if you need to remove it.
> if flame sensor has any white/black crud on it clean it with fine steel wool and reinstall. :thumbsup:


In my case when flame comes on it stays lit and works fine.


----------



## plummen (Jan 10, 2010)

try removing the vacuam line from the inducer motor and sucking through the hose,you should hear the contacts inside pressure switch close when you do this then open when you stop.


----------



## barnis (Feb 10, 2011)

plummen said:


> try removing the vacuam line from the inducer motor and sucking through the hose,you should hear the contacts inside pressure switch close when you do this then open when you stop.


I assume I open the lower panel to get to these hoses? can you explain in more detail? It's running now so I'd rather wait until we have a fault again. Can you explain your thought process for troubleshooting?


----------



## HAMP (Feb 9, 2011)

Hey Barnis, I didn't mean to hijack your thread, it was just getting cold in here and I didn't know really what to do.

To plummen:
I thought it might have been a blocked flue, took it loose and nothing changed. put it back and nothing changed.

I took the door off to maybe see if I could visually see a problem, once I took the door off, everything is working fine now.

I wasn't a brute when taking the door off, and I think the only wire I could have moved or touched when taking off was the two yellow wires in the second pic.

I am scared to put the darn door back on. can you tell me which wire I might have to work with to make it stay working properly?


----------



## plummen (Jan 10, 2010)

its a black or grey rubber hose inside top cabinet.
one end is hooked to a barb on the inducer motor other end is hooked to a round plastic canister/switch with 2 wires coming off of it.
definately wait till it quits working again before checking it ,or wait till you have some warm weather


----------



## HAMP (Feb 9, 2011)

Or maybe that little black thing in pic #4... that might have wiggled a little when the door was removed. It's part of the other door.


----------



## plummen (Jan 10, 2010)

thats a door safety switch,if its open nothing will work


----------



## barnis (Feb 10, 2011)

plummen said:


> its a black or grey rubber hose inside top cabinet.
> one end is hooked to a barb on the inducer motor other end is hooked to a round plastic canister/switch with 2 wires coming off of it.
> definately wait till it quits working again before checking it ,or wait till you have some warm weather


Is there any harm in opening either the top or the bottom panel (assuming it's warm weather?

Is your thinking that the pressure is not getting created? Would I get a 6 flash error with that?


----------



## HAMP (Feb 9, 2011)

plummen said:


> thats a door safety switch,if its open nothing will work


 ok, so not that thing. Do you see what else I could have wiggled when taking that top door off?


Those two yellow wires?


----------



## plummen (Jan 10, 2010)

barnis said:


> Is there any harm in opening either the top or the bottom panel (assuming it's warm weather?
> 
> Is your thinking that the pressure is not getting created? Would I get a 6 flash error with that?


 you can open either door anytime,not sure about the fault code numbers.
im used to having the furnace sitting in front of me,if you were within 100 miles of louisville ne id probably just drive over and look at it for ya,retirement is boring! :laughing:


----------



## plummen (Jan 10, 2010)

HAMP said:


> Or maybe that little black thing in pic #4... that might have wiggled a little when the door was removed. It's part of the other door.


thats your door switch


----------



## plummen (Jan 10, 2010)

picture 1 is an inducer motor and pressure switch and vacuam line i was talking about,this is an 80% furnace but concept is same on 90 plus furnace just differant location.


----------



## plummen (Jan 10, 2010)

in picture 1 on the top left side of burner cover the red wire closest to heat exchanger is the flame sensor wire


----------



## HAMP (Feb 9, 2011)

plummen said:


> picture 1 is an inducer motor and pressure switch and vacuam line i was talking about,this is an 80% furnace but concept is same on 90 plus furnace just differant location.


So do you think that was my problem, those two yellow wires? Should I clean the tips? or do you have another idea?


----------



## barnis (Feb 10, 2011)

*still...*

Ok so it's still happening...I double checked and it's actually an EIGHT flash error. If I look through the window I see that the ignitor never heats up when it fails to light and the gas doesn't come on. This leads me to believe that the issue is

1) lack of pressure build-up by the initial fan (is that the right term)
2) bad electronics which are sending bad signals 

It still seems odd to me that a 30 minute power cycle resets it and then it works fine...any ideas?


----------



## barnis (Feb 10, 2011)

anyone still watching this thread...it's cold and won't light at all now...wondering what I can do to get it lit...


----------



## plummen (Jan 10, 2010)

time to call somebody local to you out there,only so much can be trouble shooted over a computer and a couple guys have already tweaked things on it.
if youre someplace close to omaha ne let me know


----------



## HAMP (Feb 9, 2011)

barnis said:


> anyone still watching this thread...it's cold and won't light at all now...wondering what I can do to get it lit...


 
I see your still having problems also. Mine is odd to me. When I took the door off it started working fine, when I had time later to put the door back on, it started doing it again.

I took the door off and it works. I know I can't leave it like this, but only time I think of working on it, is when it's too cold to have it off. 

or the e-mail I got that reminded me.


----------



## college A/C (Feb 10, 2011)

*Trying to follow*

Did you find the rubber hose from the pressure switch to the inducer draft motor? Did you blow through the hose towards the blower housing and see if you can clear it? or take a small stick pin and push it through the prong sticking out of the housing to see if there was a blockage?


----------



## HAMP (Feb 9, 2011)

college A/C said:


> Did you find the rubber hose from the pressure switch to the inducer draft motor? Did you blow through the hose towards the blower housing and see if you can clear it? or take a small stick pin and push it through the prong sticking out of the housing to see if there was a blockage?


Is this for me?


----------

