Furnace burner cycles on and off


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Old 02-02-09, 06:43 PM
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Furnace burner cycles on and off

Comfortmaker 16 y.o.
Model: GUI075A012IN
Serial: R92150D826

Hi guys,

Tech today visited to replace broken igniter and said that I have other problem with furnace which he can not fix and basically offered to replace HVAC. I'll try to explain from his words and my memory.

My Comfortmaker has three burners. Relatively small part of the flame from rightmost burner (adjacent to igniter) is going up igniter, not much, but enough to cause following problem. It heats top cover plate above burners and then roll-out switch, which is connected to that plate, shuts off system when plate becomes hot enough. This happens about 2-3 min after burners start working. Then after some time plate cools off and burners start working again.

Tech tried to lower gas pressure, clean burners, nothing seems to help.

Any ideas? Please let me know if you need more info.
Thanks!
 
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Old 02-02-09, 11:31 PM
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The burners in this furnace are famous for getting badly rusted, and then plugging up the furnace with soot.

It's hard to know exactly what's causing the problem, but it's also hard to believe that it can't be corrected. Your repairman did a good job for you by identifying this problem and cleaning the burners. But I'm thinking something has been overlooked, probably a defect in the burners and perhaps a portion that has rusted out.

Replacing the burners would very likely solve the problem. If you want to take a chance on that I'd record the make, model and serial number of the equipment and shop for a repair outfit to bid the part and replacement cost. It's probably about a half hour to 45 minute job, and the burners used to be $75 retail or so. I'm guessing you'd find someone to replace the burners for $275-300 or so, parts and labor.
 
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Old 02-03-09, 07:24 AM
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SeattlePioneer,

Thank you for your help. I thought about giving a try replacing burner(s). BTW, do I need to replace all three or just one that seem to be defective? I, probably, can shop around by myself, if you point me in right direction in terms of where to look (eBay, some reputable parts suppliers, etc). From what I saw how tech cleaned burners, I'm pretty sure I can carefully replace them myself.

Also off topic question. Is $230 reasonable fee for replacing ignitor? I understand this might be lame question, I just want to get an idea if replacing $30 bucks ignitor and therefore charging $200 for 5-8 mins labor is normal in this type of business (+ $80 diagnostic fee, + $40 tuning fee).
 
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Old 02-03-09, 10:48 AM
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When I was operating my repair business I charged $95 for an hour of labor or less plus parts. An ignitor typically went for about $60.

I don't doubt I could have charged more.

Personally, I'd concentrate on finding a repairman (or other service provider) who is 1) honest and 2) competent.

An honest person isn't going to treat you badly and a competent person isn't going to charge you for things you didn't need, and will do the things that do need to be done.

The burner assembly may be one or two pieces --- you'd supply the model and serial number for the furnace and get the part(s) you need --- if people are paying attention.

Replacing the burner isn't especially difficult, but getting access to it involves removing several sheet metal covers and baffles which need to be reinstalled correctly. You need to pay attention to that.

If you were charged $230 to replace the igniter and more to diagnose the problem --- that sounds a little rich. On the other hand, the repairman sounds like he correctly identified an unusual problem, which is good. He made an attempt to solve the problem for you, which is good.

I'm surprised he didn't suggest replacing the burners. Possibly there was a reason for not doing that. But my prediction is that a defect in the burner is causing the problem.

I'd be inclined to give your repair a "B" grade based on what you've told us. I've seen worse.

If it turns out new burners don't solve the problem you can give me a "D" grade.
 
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Old 02-03-09, 11:30 AM
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Originally Posted by SeattlePioneer
The burner assembly may be one or two pieces --- you'd supply the model and serial number for the furnace and get the part(s) you need --- if people are paying attention.
Supply the model and serial number where or to whom? To Comfortmaker manufacturer?
 
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Old 02-03-09, 01:18 PM
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You could order parts through a furnace repair company if they will help you. Any outfit that sells Coleman furnaces should be able to order that part if they want to.

You could also ask Coleman retailers who the distributor of Coleman equipment is in your area. Distributors often handle several different furnace makes and sell to retailers. They usually are the principal outlet for original equipment parts.

You might find parts available on the internet.
 
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Old 02-03-09, 03:39 PM
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You have in-shot burners..they do clog up, more often then not from lack of maintenance, or proximity to chemicals ie: bleach or cleaning products. Sounds like the tech found the problem, the question should be........do you want to try to replace these burners or burner in a 16yr old furnace?
 
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Old 02-03-09, 05:49 PM
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Hello dun---

I believe the burners in this furnace are slotted, not inshot.

Unless I'm mistaken they can get pretty rusty if not cleaned and are prone to sooting up the heat exchanger if not cared for

An illustration of the burners I'm envisioning is at:

http://www.supco.com/images/pdfs/Man...ons/41-414.pdf

Figure 5 & 6 would be illustrating the burners in the vicinity of this stray flame that is apparently causing problems.

Could be wrong --- if Eternum saw the burners perhaps he can tell me if I'm barking up the right tree.
 
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Old 02-03-09, 05:55 PM
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Hey Seattle,
Nice to meet ya...what you linked me to were HSI's

I still think the tech had it and I still think its time for a new furnace

keep in touchBeer 4U2
 
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Old 02-03-09, 06:00 PM
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Further research makes me out to be a liar.

Sorry dun--- you are correct:

http://icpindexing.mqgroup.com/docum...4106103002.pdf


Still probably a burner defect, all the more likely because these burners are assembled from a bunch of individual parts, any of which could get out of alignment and cause a burner problem of the kind described.

More than likely the problem could be corrected by good cleaning and adjustment by an excellent furnace repairman, if there are any out there these days. New burners would probably not be required.

I probably wouldn't hold the repairman who was out there too culpable. He found and identified the problem and apparently did his best to clean and adjust the burners. It's always possible I wouldn't have done any better.
 
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Old 02-04-09, 07:11 AM
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Originally Posted by SeattlePioneer
Could be wrong --- if Eternum saw the burners perhaps he can tell me if I'm barking up the right tree.
Burner looks similar to this one:
http://americanhvacparts.com/Merchan.../in%20shot.jpg
 
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Old 02-04-09, 07:14 AM
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Originally Posted by SeattlePioneer
Yep. Figure 1 shows very similar unit. Difference is that I have three burners, not four.
 
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Old 02-04-09, 07:22 AM
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Originally Posted by dun11
the question should be........do you want to try to replace these burners or burner in a 16yr old furnace?
So, the point is replacing burner in 16yrs old unit is pretty dumb idea and it is time to start shopping around for a new furnace?
 
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Old 02-04-09, 09:18 AM
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In my opinion yes, I would advise one of my customers to start considering new equip. I would lean towards a 90% eff unit - something with a variable speed blower. All depends on your $ situation; how long do you plan to keep your home etc.

Good luck
 
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Old 02-04-09, 01:57 PM
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My bias would be to shop around for the best repairman you can find, because repair of the burner may be accomplished by proper cleaning and adjustment.


Should you choose to replace the equipment, I agree that there is a good argument for buying a %+ efficient condesning furnace.

The extra cost for a two stage unit depends on your pocketbook and taste for particularly quiet operation.

Personally I don't see the case for spending the extra money to buy and maintaina continuously variable furnace, although if you don't mind spending extra money for small improvements over a two stage, go for it!



Seattle Pioneer
 
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Old 02-04-09, 03:26 PM
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Originally Posted by Eternum
Comfortmaker 16 y.o.


Tech today visited to replace broken igniter ....
What kind of ignitor is this?

My Comfortmaker has three burners. Relatively small part of the flame from rightmost burner (adjacent to igniter) is going up igniter,.....
Going up the ignitor? If I knew the ignitor type, maybe I could understand this better. Right now I can't visualize. Is anybody else?


Any ideas? Please let me know if you need more info.
Thanks!
Has that far burner's orifice been looked at? Or checked inside of the manifold that supplies gas to all 3 burners? Any air shutter control that is different on that burner compared to the others?
 
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Old 02-05-09, 08:29 AM
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Originally Posted by ecman51`
What kind of ignitor is this?
Hot Surface Ignitor Comfort Maker 1096048

Looks like this one.
 
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Old 02-05-09, 09:14 AM
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Originally Posted by ecman51`
Going up the ignitor? If I knew the ignitor type, maybe I could understand this better. Right now I can't visualize. Is anybody else?




Has that far burner's orifice been looked at? Or checked inside of the manifold that supplies gas to all 3 burners? Any air shutter control that is different on that burner compared to the others?


Presumably what's happening is that a portion of the burner flame isn't being directed into the heat exchanger as it should be. Instead, it's backing out of the furnace and causing the flame rollout switch to open.

Your suggestion of checking the burner orifice for a defect or obstruction that might be causing this and cleaning the orifice would be a good one to do, although more likely in my opinion would be some plugging or defect in the burner itself.

Both would be worth checking.
 
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Old 02-05-09, 09:28 AM
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Originally Posted by SeattlePioneer
Presumably what's happening is that a portion of the burner flame isn't being directed into the heat exchanger as it should be. Instead, it's backing out of the furnace and causing the flame rollout switch to open.
This is exactly what is happening.
 
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Old 02-05-09, 03:56 PM
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When does this backing out of the flame occur?: Right off the get go?, or when the blower motor (that makes air come out the resisters) comes on? And can you actually see the flame back out, or are you going by the fact the roll-out switch trips?
 
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Old 02-05-09, 04:11 PM
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Originally Posted by ecman51`
When does this backing out of the flame occur?: Right off the get go?, or when the blower motor (that makes air come out the resisters) comes on? And can you actually see the flame back out, or are you going by the fact the roll-out switch trips?
Flame (well, small portion of it from rightmost burner) is backing out from the moment burner starts working, this is in no way related to blower. And yes, it is absolutely clearly visible. After 2-3 minutes roll-out switch shuts off the system.
 
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Old 02-05-09, 04:26 PM
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Did the tech try to disconnect the exhaust pipe from the inducer for at least a few seconds to see if the flame straightens up then?: To rule out an obstruction in the vent pipe.

The pressure switch normally would shut down the burners flame. But who knows what might trip out first, especially if maybe at one time the pressure switch was replaced with something generic.
 
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Old 02-06-09, 07:38 AM
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Quite honestly I have no idea if tech did something with exhaust pipe. I'd think he did not, since he never mentioned that to me.

Switch shuts down burner flame, you're correct, not the whole system, as the one might think from my previous post. I was not very clear on that.

What is the recommended way of finding contractors for installing new furnace/ac? Asking neighbors, I assume. Is there any resource in the Internet where people share their experience about contractors from different regions?
 
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Old 02-06-09, 08:54 AM
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It is, of course, up to you whether you decide to spend money on another attempt to repair the burners or replace the furnace. To my way of thinking, there is no reason to replace the furnace when all that's needed is that a clearly defined problem needs to be corrected.

I'd be inclined to shop around amonf repair outfits in your area that sell Coleman furnaces and try to find a repair outfit familiar with your furnace. You can tell them that you need someone who can remove and clean the burners in your model furnace. Someone ought to be able to do that for you, and more than likely that's all that needs to be done.

It would be pretty sad if someone needs to replace their whole furnace because no one can be found to competently clean the burners on a furnace.


But it's up to you.

Good luck.
 
 

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