# Older Carrier Pilot Burner Problem



## cliffkot (Oct 14, 2010)

I have an older, model 58SE Carrier furnace that stopped working. The pilot lights but the MGV will not open. The furnace has electric ignition and uses an Intermade pilot burner, and 24vac (actually measures 28vac.) If I short the connections, wht/yellow on the pilot burner lead, the MGV opens and 
everything runs great. Further tests revealed that the MGV will open with as little as 16vac at 250 ma. (0.250 amp).

I got an new pilot burner from PSINtermade. Installed it. Same problem. Decided to check the new pilot burner by disconnecting the cable from the circuit and operating the gas valve by jumpering. The pilot burner NC contacts (Yel/Grn wires) read 0.7 ohm closed. Within 10 seconds
of lighting the pilot, the NC contacts opened. If connected they would have dropped the pick valve and igniter off line. This is normal. 

I then checked the NO (cold) contacts (Yel/Wht). They were still open. In the circuit, had they been connected, the MGV would not have opened. I waited a minute. Same thing. 2 minutes 3 minutes,... 10 minutes. Nothing. Still open.

The pilot flame looks good, envelops the whole head of the pilot burner with enough flame squirting out the right hand side to enter the main burner chamber. 

PSintermade claims they checked the burner before it was sent. What is wrong?

While I'm not an HVAC guy, I am an electrical engineer with a lot of experience. This is a simple bimetallic switch, or so I'm led to believe. 

Any ideas?

Cliff


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## yuri (Nov 29, 2008)

Why would they test the burner(sounds suspicous) and how did they do it w/o a furnace. The ones I get are in a sealed bag and never have a problem. I prefer the OEM Carrier one rather than the generics. Make sure you get a nat.gas one and not a propane one as it has a smaller orifice/unless you are using Propane.


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## kenmac (Feb 26, 2009)

If you have the old 3 or 2 wire bryant / carrier bi metal pilot. The flame isn't hot enough to bent the metal or the metal is bent out of original shape & make the circuit. Like Yuri said. make sure it's for the correct gas



Like this


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## cliffkot (Oct 14, 2010)

yuri said:


> Why would they test the burner(sounds suspicous) and how did they do it w/o a furnace. The ones I get are in a sealed bag and never have a problem. I prefer the OEM Carrier one rather than the generics. Make sure you get a nat.gas one and not a propane one as it has a smaller orifice/unless you are using Propane.



Well I don't think there is an OEM supplier for Carrier anymore except Psintermade. I think they put a lot of companies out of business, I can't find any other manufacturer. 

What happened is that a couple of years ago my furnace started cycling every couple of seconds. I jumpered the pilot burner switch and it worked fine, so I got a new pilot burner. It fixed the problem. This year it quit again. 

I contacted the manufacturer and they sent me a new one, I sent them the old. Put it the new one. It didn't work. They claim the old one is OK too. Well obviously something isn't right. Thats when I decided to do some critical testing of both the pilot burner and Main Gas Valve. I found that my valve works beautifully. Pulls in with a measly 16vac and .25 amp. On the other hand the new pilot burner never closes after it heats up. The NC contacts open quickly(10-15 secs), as they should after the pilot lights, but the Normally Open (NO) contacts never close. 

The only unknown for me is the size of the pilot flame. It looks good, but who knows.


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## cliffkot (Oct 14, 2010)

kenmac said:


> If you have the old 3 or 2 wire bryant / carrier bi metal pilot. The flame isn't hot enough to bent the metal or the metal is bent out of original shape & make the circuit. Like Yuri said. make sure it's for the correct gas
> 
> 
> 
> Like this


That's the part all right. i used the orifice that they sent me. how can you tell which is which?


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## kenmac (Feb 26, 2009)

You would have to take the orifice out . I put the orifice on top of a flashlight. If you haven't seen a propane orifice vs ng you might not be able to tell the difference. Propane is smaller hole. Like yuri said . unless they connected it . How would they know it worked


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## cliffkot (Oct 14, 2010)

kenmac said:


> You would have to take the orifice out . I put the orifice on top of a flashlight. If you haven't seen a propane orifice vs ng you might not be able to tell the difference. Propane is smaller hole. Like yuri said . unless they connected it . How would they know it worked


They told me they have a testing machine that duplicates a furnace.


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## kenmac (Feb 26, 2009)

cliffkot said:


> They told me they have a testing machine that duplicates a furnace.


 

It's not getting hot enough or there's something wrong with the wire connections in the assy


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## yuri (Nov 29, 2008)

IMO it would be very difficult to simulate a furnace as it has draft and a lower temp than some bench tester. Your pilot regulator may be sending too low a pressure to the unit. That is a gnarly old furnace with a heat exchanger that is ready to fail.I had one with a intermittent sticking gas valve that caused a huge bang/delayed ignition from not opening fast enough and the timing was off. Unsafe to use and scared the customer half to death with a gas smell. If it is the mid efficiency unit with the board behind the ventor fan those are a nightmare to troubleshoot and that board can damage the lower board. We sort of abandoned a poster a while back because very few guys know how to service that old unit and could not help him. You may be on your own. I would look into a new furnace or be prepared to spend lots of time and $$ trying to keep it running. After 25 yrs there is not a great demand for parts and the manufacturers start dwindling down the OEM parts supply and the generics are not nearly as good. All about supply and demand.


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## cliffkot (Oct 14, 2010)

kenmac said:


> It's not getting hot enough or there's something wrong with the wire connections in the assy


I was thinking about not getting hot enough. Do you know whether the pilot flame is supposed to be 2 stage. In other words is it hotter before the burner kicks in ? 

Will the pilot flame reduce when the pick coil is de-energized?

Does anybody know?

cliff


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## artbuc (Dec 4, 2008)

cliffkot said:


> I have an older Carrier furnace that stopped working. The pilot lights but the MGV will not open. The furnace has electric ignition and uses an Intermade pilot burner, and 24vac (actually measures 28vac.) If I short the connections, wht/yellow on the pilot burner lead, the MGV opens and
> everything runs great. Further tests revealed that the MGV will open with as little as 16vac at 250 ma. (0.250 amp).
> 
> I got an new pilot burner from PSINtermade. Installed it. Same problem. Decided to check the new pilot burner by disconnecting the cable from the circuit and operating the gas valve by jumpering. The pilot burner NC contacts (Yel/Grn wires) read 0.7 ohm closed. Within 10 seconds
> ...


I have two 20 year Bryant units with the infamous 3 wire pilot sensor. One unit never gave me a problem. The other had a 3 wire pilot failure about 6 years ago. I replaced it with a new factory OEM unit which has never operated right. It takes several minutes to satisfy. Sometimes, when it is very cold and the unit has not been run for a while, the bimetallic switch never closes and the furnace locks out. I put up with this because I don't want to shell out $100 for a new pilot. I have done a fair amount of research on these 3 wire pilots and they are notoriously unreliable even when brand new.

If I read your post correctly, you have confirmed that the 3 wire pilot is not closing even when exposed to a strong pilot for several minutes. If this is true, you need to get a new one.


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## kenmac (Feb 26, 2009)

cliffkot said:


> I was thinking about not getting hot enough. Do you know whether the pilot flame is supposed to be 2 stage. In other words is it hotter before the burner kicks in ?
> 
> Will the pilot flame reduce when the pick coil is de-energized?
> 
> ...


 
No & it shouldn't. Most of these That I use to see in the field were set up for pilot to burn all the time


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## cliffkot (Oct 14, 2010)

*Pilot Burner Test*

To test my idea of insufficient pilot flame, I fired up the pilot and then added some supplementary heat to the pilot burner module itself with a small flame from a propane torch. The pilot burner contacts still failed to close.

Not what do you guys think.

Cliff


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## cliffkot (Oct 14, 2010)

artbuc said:


> I have two 20 year Bryant units with the infamous 3 wire pilot sensor. One unit never gave me a problem. The other had a 3 wire pilot failure about 6 years ago. I replaced it with a new factory OEM unit which has never operated right. It takes several minutes to satisfy. Sometimes, when it is very cold and the unit has not been run for a while, the bimetallic switch never closes and the furnace locks out. I put up with this because I don't want to shell out $100 for a new pilot. I have done a fair amount of research on these 3 wire pilots and they are notoriously unreliable even when brand new.
> 
> If I read your post correctly, you have confirmed that the 3 wire pilot is not closing even when exposed to a strong pilot for several minutes. If this is true, you need to get a new one.


Where did you get the info on their unreliability? I need some ammo because I'm going to have to argue with a manufacturer.

thanks


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## artbuc (Dec 4, 2008)

Sorry, I can't give you anything definitive. I just remember asking about my problem on several DIY/HVAC forums and got many remarks about poor design/reliability of these pilot assemblies. I doubt if anecdotal experience will help you too much.


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## cliffkot (Oct 14, 2010)

*Received Another Pilot Burner from PSIntermade*

As promised, I just received another pilot burner from PSIntermade. Unfortunately, I'll be away from home for several days and won't be able to get to this until next week.

I examined the package carefully. There is no evidence that it was specially tested before being sent to me, no restapling of the package etc. Likewise with the inner package. It was sealed once. 

I then examined the part and connectors with a jewelers' eye loupe. I could find no evidence that the part had ever been hooked up. The electrical connections showed none of the characteristic micro scratching that happens when they are pushed together. The spark electrode shows no evidence that it has ever been sparked. The burner and flame diverter show no discoloration. I don't believe the unit was ever tested. 

My plan is to install the part, light it for 1 minute (I'm sure it won't work) and then examine it carefully to see if I can detect whether it has been used. If I can, I know it was never tested, contrary to what I was told.

I've been doing some internet surfing and discovered that some outlets are selling Carrier OEM parts. Are these really Carrier parts? The company that originally sold me the replacement burner said the OEM stuff was no longer available. 

I'm beginning to think that the people in this business are a little unethical.


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## kenmac (Feb 26, 2009)

If you don't know how to check. I would have this furnace inspected. They were not a very good design & are known for holes / cracks in the combustion chamber. In years past when I replaced 1 of these pilots . I never had a problen with a new pilot assy. Don't see many of these furnaces any more.Most have gone to furnace heaven


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## cliffkot (Oct 14, 2010)

kenmac said:


> If you don't know how to check. I would have this furnace inspected. They were not a very good design & are known for holes / cracks in the combustion chamber. In years past when I replaced 1 of these pilots . I never had a problen with a new pilot assy. Don't see many of these furnaces any more.Most have gone to furnace heaven



Thanks for the concern. Inspecting the heat exchanger was one of the first things I did. I used an inspection mirror as much as possible and then checked for air leaks with a candle flame. Found one tiny hole in front, about the size of a #50 drill bit. 

I'm sure you never had problems with a new US made pilot burner. That's the problem. I think my supplier was untruthful when they told me the parts were not available. I'm trying to get a hold of Carrier to find out how I can be absolutely sure that if I buy a part with their name on it, I'm really getting their part. There are a lot of counterfeits out there. 

A couple of years ago the Square D people had a big problem with people selling knock off circuit breakers under their name. They weren't even circuit breakers. They were switches made to look like circuit breakers. Apparently they were being sold by a major retailer. Never could find out who, though, it was hushed up.


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## yuri (Nov 29, 2008)

Carrier sold 100s of thousands of rooftop units with those pilot burners so I imagine they will still produce their own 3 wire pilot for awhile. They don't like supplying non OEM parts.


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## kenmac (Feb 26, 2009)

that tiny hole will become a larger hole. I don't like any holes in the chamber


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## cliffkot (Oct 14, 2010)

*Success!*

I discovered that Made in USA Carrier parts are available and ordered a new OEM pilot burner assembly from Shorty's HVAC Supplies, in Indianapolis. They are very helpful and courteous and offer free FedEX ground shipping. I got the part the next day. 

I popped it in, removed my bypass jumpers, opened the master shutoff and flipped the switch. Spark, spark spark. The pilot lit. I held my breadth. After what seemed like an eternity (45secs), I heard a click, then a whoosh, and stared into the most beautiful blue flame I ever saw. Heat at last! (I'm now the hero around the household again.)

Moral of the story. Do not buy PSINTERMADE. It is ****** crap! They told me they tested the pilot burner before they shipped it. They lied. 
I put the part under a microscope and found no metallic sputtering on the electrode, no scratches on the connector surfaces, no discoloration around the pilot and diffuser. You can heat it until it turns red and it will not close. The Carrier part on the other hand had been tested. You could see the discoloration with the naked eye (and my naked eyes are not so good anymore). I learned a good lesson. 

Here is a link to Shorty's. They are great folks and sell only OEM. 

Cliff 

http://shortyshvac.com/


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## zephxiii (Apr 29, 2011)

Just saw this thread and wanted to comment. 

The PSINTERMADE is not an OEM part, it is reverse engineered from the original OEM part which means it is not based off the original drawings, materials and testing. 

The original OEM part is still being made (here in the United States)to this very day and strictly follows the originally based drawings, material specifications, and testing. 

I have personally ran both parts through testing and seen the PSINTERMADE parts fail in the first phase (bi-metal switch failure). I've have not yet seen an OEM part fail any phase of the testing (as it's actually a pretty good piece!). 

Stick with the OEM replacement parts. It will save you a lot of trouble.


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## cliffkot (Oct 14, 2010)

*PS Intermade Junk*



zephxiii said:


> Just saw this thread and wanted to comment.
> 
> The PSINTERMADE is not an OEM part, it is reverse engineered from the original OEM part which means it is not based off the original drawings, materials and testing.
> 
> ...


Yes, that is what I discovered. What really irritated me is that I had several conversations with PS Intermade. They deceived me about their quality control, and tried to make me believe their part was OK (after all I had 3 of them, all no good) and that my furnace was bad. In short, THEY ARE A BUNCH OF LYING SOB'S who sell Chinese crap! 

I wish I could say what I really think of them, but this is a public forum and decorum prevents me. 

In any case thank you so much for the affirmation. The PS Intermade guy was playing made games on me and had me doubting my sanity. I set up a whole test station, complete with IR thermometer, timer, valve body - the whole works. All the while the wife was on me to get some heat in the house. 

Finally in desperation I started searching for someone who might have an original part (after being told that they were no longer manufactured), and discovered that they were in current production. Got it in a day or two, popped it in and had heat in five minutes. 

Just a word to the wise, fellows.

Thanks again for your post 

cliff


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## zephxiii (Apr 29, 2011)

No Probem!


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