Furnace burners not firing.. pilot goes out quickly


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Old 02-09-05, 08:04 PM
Luap
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Furnace burners not firing.. pilot goes out quickly

Well, my post got killed by a browser thing... ARGH!! I'll try this again:

I searched the forums for help on this, but didn't figure anything out. Please excuse me if this is a repost or such.

I have a warm air furnace, circa 1990 that is having issues. The pilot light comes on very briefly before blinking out. There is an electric ignitor and an automatic gas valve that turns on/off within 0-3 seconds of the pilot lighting.

I've checked everything I can think of (and what I've read about) and I'm leaning heavily towards a "flame sensor" problem... thing is, I can't figure out what the flame sensor is exactly on this unit. Here's why:

The ignitor assembly has two parts to it: the aluminum gas line, and another white (not porceline, I think) cylinder with a metal "tip".. this has a wire connected to it (looks like a spark plug wire).

My first guess was this white cylinder was the flame sensor, so I buffed the metal tip (about 3/4 in. long) with emery cloth, but this didn't do anything obvious. Later, I realized it was the ignitor, but it sure looks like and is placed like a flame sensor from what I've been reading... could it be both? I don't know what I'm talking about, so maybe that's a foolish question, but it sure seems like a flame sensor would be right in the thick of the flame like that, eh?

Anyway, I'm now holding in my hand the only other part from the whole burner compartment that had wires running into it... my hope is that this thing is in fact some sort of "flame sensor" or equivalent and that it's dead and replaceable... here's what it's like:

It's mounted on a metal bracket at the rear of the burners, away from the end with the pilot light. It's a small (1/2 in. square) cylinder with two wire connectors coming out the back (side away from the front of the burners). There is also a small "pin"-like protrusion that appears to have an insulator around an inner pin.. this insulator-lookin' piece slides very slightly in/out, maybe 1mm or so. The other end of the cylinder faces toward the "front", in the same direction as the burner outlets... it's a flat metal face.


Well, that's about it. I'm sick of typing, since this is my second time through this post... and I'm sure you're sick of reading this verbose mess! Sorry 'bout that. Please give me an idea of what I'm looking at here and if it's the answer to my problems! I'll try again running around town asking parts shops, but today's excursion was less than fruitful.

Thanks HUGE!!
Luap
 
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Old 02-10-05, 05:38 AM
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Actually it's a pretty decent post for a 1st timer. I moved it to the gas furnace forum so you'll get more gas experienced people reading it.

If you know the make, model and serial # of the furnace that will also help.

Now to your problem. Are you saying that it will spark and the pilot will light then the main burners light then in a few seconds the burners go out?

If you have any way of hosting a picture of the part in question or e-mailing it that helps also.
 
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Old 02-10-05, 08:22 AM
Luap
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Gah! I'm sorry about the forum... I think I was posting it under this one, but when the thing got killed off, I must have come back in to the wrong place. Well, that or I may have just been too sleepy when I posted it? :P

Thanks for the feedback. Here's the extra info that I could get real quick.. I need to run so if there's more info I need, I'll post it later.

Central Environmental Systems made the furnace, dated 1990 on the label.
P-HED12NO6001A (on another label, I saw "1 or A")

Here are photos of the part... should have just done that in the first place, I guess. Would have saved me a lot of pain trying to describe it.

http://www.nearlyeverything.com/furn...part-front.jpg
http://www.nearlyeverything.com/furn..._part-back.jpg

Thanks again for the mere potential of help!
 
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Old 02-10-05, 08:46 AM
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Lightbulb

Thanx for the pix. That is a manual reset roll-out switch. If the pilot comes on than the switch is closed. I am leaning toward a problem with the board or module. i.e grounding, loose wire, bad module or maybe tstat heat anticipator needs adjust. Would you be able to post some pix of the board or module and the control area?
 
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Old 02-10-05, 11:09 AM
Luap
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Okay.. I'll work on getting some more photos if I can. There's a main box that has all the wires from various units running in/out of it. I'm guessing this is what you're talking about. I had a hard time getting that cover off before, so I'll give it another go.

Also, I neglected to clarify earlier... there is a spark from the ignitor, the pilot lights and then goes out within 2 seconds, but usually almost 1/2 second or so. The main burners never light. Thus, the automatic gas valve dealie gets a workout as it's opened & shut right after the pilot gets lit.

If I turn off the gas, the ignitor will sit there clicking/sparking indefinitely, in case that's any help. As soon as I turn the gas back on, I get the same behavior.. pilot lights and then everything shuts off and it goes out.

Thanks... I'm gonna crawl under the house again. :P
 
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Old 02-10-05, 03:20 PM
Luap
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I got into the main board panel and took some shots. I honestly (and embarrasingly,) don't know exactly what you are asking for pictures of, so I'll start here. What exactly do you want to see more closely and I'll gleefully snap some more... yes, I said "gleefully"... my trip to the heating/plumbing parts store just added to my frustration level, so I'm just happy to get some help!

Check these out and tell me what else you'd need:
http://www.nearlyeverything.com/furn...ace_board1.jpg
http://www.nearlyeverything.com/furn...ace_board2.jpg
http://www.nearlyeverything.com/furn...rnace_ext1.jpg

One note about what I saw... I wriggled all the connections to see if they were snug or if anything was obviously not right -- looked okay. Also, there is a place on the right side for a possible pin-out for "sensor", but it isn't being used... would that be the "flame sensor" type unit I've been searching for?? If so, it apparently wasn't ever there, and there's no place to plug one in anyway.

Lastly, what exactly is "the module" in this case? I am a computer tech-type guy so I understand what the circuit board is all about, but you're referencing "modules" and I don't know what they are or how you'd know if they were bad.

Thanks again.
 
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Old 02-10-05, 09:24 PM
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I would say it's your ignitor control box (Grey box) is the fault.

Just make sure the ground wire is good..
 
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Old 02-11-05, 12:24 AM
Luap
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Well Jay, I went through all the wires leading in/out of that grey box... I couldn't find any loose connections and I checked snug-ness, etc... no change in function, or lack thereof.

Is there some sort of fuse or such that might be blown inside that ignitor control? Several of the wires coming out of the box that are apparently ground-related are plugged into an orange plastic pin-block that is mounted to the automatic gas valve assembly (which is where the pilot on/off dial is, etc.) One of these wires is labeled "24V ground", I believe. That orange block appears to be removeable, but I didn't try... would that be a replaceable element to this equation??

Also, the wire labeled "GRND Burner" is plugged into it's own pin directly on the metal block of the gas valve assembly.

Hopefully I'm covering all bases here, but please forgive me if I'm missing some point. Thanks again.

...and again.
 
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Old 02-11-05, 05:19 AM
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The control box is not servicable.

There should be a flame sensor right there with the pilot.
 
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Old 02-11-05, 09:34 AM
Luap
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As far as I can tell, the only possible part that could be a flame sensor is the _same_ part as the ignitor! There are only two pieces to the pilot assembly: the aluminum gas line (bent at the end to angle over about 45 deg.); and the ignitor, which is the only piece with a wire running into it.

I have read that the flame sensor and the spark ignitor could be the same part, but as far as I can tell, there's nothing on the ignitor control box that plugs into anything called a "sensor". The ignitor piece has the wire connected to it, and it's very similar to a spark plug (car) connector... one wire. This wire is plugged into the ignitor control box labeled "spark". At the place on the box labeled "sensor", the leads don't even exist, so nothing can be plugged into that place.

I tried very hard to get the ignitor removed from the burner unit, (hoping to get a replacement) but it's not easy at all. I honestly started to figure that if it was something meant to be replaced or serviced, that it would be made easier to access... I'm sure that's a naive assumption! ) I guess I'd have to remove the whole burner assembly, but that entails somehow unscrewing gas lines and such... I'm not willing to get into that, since I'm not knowledgable/comfortable with gas yet.

I made a valiant attempt to "buff" the metal pin-like end of the ignitor, originally thinking it was the flame sensor, and from what I can see, it's fairly cleaned.

Ugh.

Please advise on what the options are if that part is in fact the flame sensor, and it may be failing somehow... if I sanded the end with emery cloth and it made no difference in operation, what's the next move?? I guess I'm getting closer to the breaking point and calling a tech, but financially, that's as a bad thing... except I've got the furnace pulled apart now, which may be less time on his/her part! (I'm sure they'll be pissed that I'm mucking around in there.)

Thanks again for any help. The house is only getting down to 60deg., which I find tolerable, but the wife unit grows more impatient every day! LOL.
 
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Old 02-12-05, 05:42 PM
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Hey here you can find all your questions answered by honewell about honeywell controls.
What you have is a honeywell ignition module S8600 __ ______ .
Go to this web site accept the terms and type in the modle number of the control and the will give you installation instructions and trobleshooting instructions.

http://hbctechlit.honeywell.com/Defa...TOKEN=83305413
 
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Old 02-13-05, 02:11 PM
Luap
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Thanks, scottg.

I read through the appropriate docs (I have SH600H, Rev A. 97-3998). So far, I'm still pretty stuck and getting closer to calling a pro.

I tested a couple things from the document and have had nothing come up as the obvious problem. Mainly, I found out that the sensor and ignitor are in fact the same part with this model. Unfortunately, removing the sensor so it can be thoroughly cleaned is extremely difficult without disconnecting gas pipes, which I won't do.

Also, I checked some quick voltages across posts mentioned in the docs, and it seems like everything's good. I don't know if there's still a grounding problem, but I checked everything I could think of... I don't know what else to look for on that front.

I'm back tho thinking it's a sensor problem, but don't know if it's the ignitor/sensor part or something at the ignitor control module... either way, I'm about at my limit of capability. I thought about getting a new module and replacing it, but I don't know what that's going to cost or if it's even going to help since it could just be the sensor.

Thanks again for any other advice any of you have. I appreciate the feedback so far.
 
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Old 02-14-05, 06:57 AM
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At least you know your limit. When you call the pro have them also clean and safety check the furnace if it has not been done in a while.

Keep us updated.
 
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Old 02-16-05, 01:13 PM
Luap
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Quick update...

I tried again to clean the pilot assembly area, but it isn't appearing to help. It's very difficult to get at so it's not getting cleaned very well and it is proving very hard to remove. If I get some spare time (I'm working a lot right now), I'll try getting the whole assembly removed so I can thoroughly clean it up. (I hope to do this anyway, but it's a bugger.)

However, I've ordered a replacement ignitor control module (Honeywell S8610U-1003, which replaces a ton of different models) and will install that later this week.

Hopefully one of these two actions will solve this sucker.
 
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Old 02-25-05, 01:17 PM
Luap
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Okay.. got it working. Here's what happened:

The replacement module ended up solving the problem. At first, I thought it was a dead module when it didn't even fire the ignitor, but I found out I had hooked it up wrong. I wanted to post about this issue here, since it was a simple thing that was difficult to find info about.

My old module was also an S8610U, but it had different posts for plugging in the wires. The new one has a jumper in place for furnaces that don't have a separate flame sensor (like mine). There is also a "TH-W" connector, which my old one did not have the pins in place for. (Actually, the space was on the board for those pins, but the pins themselves were physically gone.)

So, here's the kicker... When you're plugging in a module like this new one I describe, but you didn't have the TH-W wires on your old one, you need to plug the 24V power into the TH-W connector. That is to say that you will not have anything plugged into the 24V power, but you move that wire over to the TH-W.

The heat is steadily rising in my house and I'm very satisfied to have saved a lot of cash... yes, it cost me quite a bit of time, but since I have time to spare but not the cash.. it's a fair trade for me.

Lastly, the ignitor module was available locally for at least $165 but I bought one off eBay for $60. Shop around, I tell ya!

Thanks again for all the help I got on this mess!
Regards,
Luap
 
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Old 01-27-07, 06:56 PM
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I'm having the exact same problem

Hello Luap,
How has this repair been working for you? I am having the same exact problem with my Rheem HVAC. I have the s ame Honeywell Ignition module too. Any further issues?

Take care.
-Sean
 
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Old 01-30-07, 02:12 PM
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Instead of replying to a 2 year old post, you should start a new thread..
 
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Old 02-03-07, 04:25 PM
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Thanks, but I don't need to. Furnace is working fine now thanks to this thread. Glad that they don't purge out good info like this!
 
 

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