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Carrier Gas Furnace not Igniting?

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  • Jan 29th, 2012 5:22 pm
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[OP]
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Oct 22, 2004
382 posts
7 upvotes
Markham

Carrier Gas Furnace not Igniting?

We have a Carrier Weathermaker 8000 gas furnace. As of a few days ago, it hasn't been working properly.

It'll start the burner and try a few cycles, but the gas doesn't ignite. After about 4-5 tries, it just shuts off. I have to manually power off/on the unit for it to restart and do the same thing over again.

Is there anyway to safely check whether there's a problem in the gas line? Or could it be the control board? The main problem is that the gas isn't igniting, the burners are firing so I would assume it's something to do with the gas intake valve.

I know next to nothing about heaters though, so any help would be appreciated.
Heatware: Rhombuss
24 replies
Deal Addict
Sep 19, 2005
2834 posts
38 upvotes
I have had this happen a few times in the past 5yrs,,,,, cant remember the exact term,,, if you check your codes it will tell you.

easy fix that u can try is,,, if you take the cover off so you can see the burners,,, you will see a skinny metal pointy rod sticking out around the burner,,,,,, get some emery cloth and rub it to clean it up,,, this should fix it.

any questions pm me
Sr. Member
Jan 3, 2005
632 posts
16 upvotes
fireguy9 wrote:
Dec 14th, 2006 9:40 pm
I have had this happen a few times in the past 5yrs,,,,, cant remember the exact term,,, if you check your codes it will tell you.

easy fix that u can try is,,, if you take the cover off so you can see the burners,,, you will see a skinny metal pointy rod sticking out around the burner,,,,,, get some emery cloth and rub it to clean it up,,, this should fix it.

any questions pm me
This is the flame sensor. I've had this exact problem myself and the symptoms are the same. A good cleaning as suggested is the fix for it. I removed mine and used some scotch brite to clean it.
Deal Addict
Sep 19, 2005
2834 posts
38 upvotes
was just going to re type the exact name,,, was beaten to it. Cleaning the flame sensor should do the trick. The sensor never looks dirty but they do get dirty and thats when problems happen
Deal Addict
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Nov 16, 2003
2584 posts
22 upvotes
Toronto
Our 6 month old Carrier furnace also had some ignition rpoblem, but it was because the vent motor wasn't turning, had that repalced under warrenty. It shuts of the ignition cycle because it can't vent the gas. Second motor got stuck aslo, found out the pipe leading outside is partially blocked by some stucco..

The best thing to do is read the codes, look at the flashing LED then the furnace cover to see what they mean.
[OP]
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Oct 22, 2004
382 posts
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Markham
Perfectly safe to turn the unit on with the cover off? I'm assuming it is, since the cover isn't sealed or anything. Just the fear of blowing myself up is quite prevalent :P.

If so, I'll fire it up and check the LED sequence.
Heatware: Rhombuss
Deal Addict
Sep 19, 2005
2834 posts
38 upvotes
the led sequence will continue to flash if there was a shut down,,,, once you shut the power down and back on it erases the memory sometimes.

just go look at the furnace lights, and read the code,,, most furnaces have the code definitions on the cover,,,,, odds are very good from what you said,,, that its the flame sensor,,,, clean it,, if it works,,,, u just saved a good $100 service call
No dangers,,,
[OP]
Member
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Oct 22, 2004
382 posts
7 upvotes
Markham
Just opened up the furnace, it doesn't want to turn on while the covers are off, so I couldn't get a look at the LED sequence. I think there's a momentary-pushbutton switch that's required to close the circuit before it turns on. I guess I could just use my finger and keep it depressed while I turn it on?

Anyway, I took a look inside. Looks like 4 burner "jets" side by side, and I think I saw a small bent rod about 3-5mm thick. I'm assuming that's the flame sensor?

In terms of cleaning it, is there a way to pull it out? I didn't notice any detach mechanism other than all the hex bolts securing the assembly into place. Seems pretty tight in there too, I doubt I could fit my hand in there.

Ideas? Thanks guys.
Heatware: Rhombuss
Deal Addict
Sep 19, 2005
2834 posts
38 upvotes
just run the furnace and if it shuts down then you can get the codes,,,, but no problem running with cover off

sounds like thats the sensor,,,
mine was a bit of a reach,,, was able to get hand in with emery cloth and clean it up a bit,,,,
otherwise you remove it
Deal Guru
Aug 2, 2001
12998 posts
3782 upvotes
When I got my last furnace cleaning (I have a carrier as well), I watched and the guy had the flame sensor removed (Along with all the burners) in under 5 minutes. It seemed fairly intuitive.
Member
Dec 26, 2003
260 posts
6 upvotes
Mississauga
I had similar problem last year . The problem was the ignition it wasn't giving any spark .Replaced it and it was fine
[OP]
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Oct 22, 2004
382 posts
7 upvotes
Markham
Opened her up, turn it on and checked the LED sequence. It's telling me "Ignition lockout".

First recommended step was to clean the sensor, I rubbed it a bit with one of those green woolie pads, but not sure if it was enough. It didn't appear to have any oxide buildup, since there was no powder residual on my scowering pad. Turned it on again, and the same thing happened.

So to clarify, the igniter does light up, the system just isn't opening the gas valve (I think).

So either I didn't clean the flame sensor enough (any way to tell?), or it's something else. But the system IS telling me it's an ignition lockout, so I doubt it would be a problem with the control board or gas valve?
Heatware: Rhombuss
Deal Addict
Sep 19, 2005
2834 posts
38 upvotes
could not see any oxide build up on mine,,, and I rubbed it really good with emery cloth,,, and since then,,, not a single shut down,,,, and it was quite regular prior to that.

you are getting enough air flow? no dirty filters, from pets, cold air returns clogged up?
Sr. Member
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Mar 15, 2003
601 posts
36 upvotes
Sorry to bump this old thread, but my carrier is acting up like this thread, ignition lockout...does anyone know where i can find the flame sensor on a carrier, i want to clean it but dont know where to locate it.

thanks.
Deal Guru
Aug 2, 2001
12998 posts
3782 upvotes
thesober wrote:
Dec 25th, 2007 1:26 pm
Sorry to bump this old thread, but my carrier is acting up like this thread, ignition lockout...does anyone know where i can find the flame sensor on a carrier, i want to clean it but dont know where to locate it.

thanks.
Mine is on the far left hand side in front of the burner. You see a metal thing poking up in front of one burner, and that is what it is.

You can probably google your model of furnace too.
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