# Heil Furnace Burner Problem



## JimK

I'm having the same problem, but the blower is set to auto. It's happening more and more often. I've had the exhaust fan (blower?) changed and the problem is still there (the fan had a noisy bearing, so it needed to be changed anyway.) Fan starts for 15 seconds, igniter fires and no burn - just see a little flicker through the check window. I'm hoping somebody knows what this is caused by. Haven't found anything online yet.


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## redline

timothyr said:


> but a few times the pilot would light but the blowers would try to start but go out immediately. The furnace would then just blow cold air until I reset it. The pilot light stayed lit the entire time. He cleaned the ingniter and pilot, but it didn't make a difference.



(confused)

The ignitor is the pilot. The ignitor lites the gas as it comes out of the gas valve.

When you say that the pilot light stayed lit - are you saying the ignitor was glowing?


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## timothyr

Sorry for the confusion. The pilot is lit and I believe the ignitor is glowing as well. The main burners aren't lighting. This only happens if the fan is set to the "on" position on the thermostat.


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## JMarshall

I'm having the same experience with my DC90 that was also installed in 1999. It does it in auto and the problem has exsisted for 3 years now. I have replaced the control board and flame sensor with no resolve. I'm trying to get Heil to address this problem but so far they have not been very cooperative.


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## #CARRIERMAN

Hi timothyr

It sounds like you have a smart valve set up on your furnace, I this is so the only way to fix this problem is to replace the gas valve. If it does have the smart valve system, the gas valve has the flame ignition and proving circuit built in. And the answer to your next question,they are very expensive.

Good luck, let me know if I can help.
Rusty


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## mdshunk

The only thing "smart" about the Smartvalve was the business decision to use them in furnaces. They are a boon to the HVAC service industry, as they are all too common failure items.


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## Wolffman

I have this same issue.
At times the furnace operates properly but many times once it reaches it preset temp and switches off it won't cycle back on. If I do a power cycle on it it functions as designed until the next cycle.

I am not 100% sure but at the end of the A/C season it seemed to be doing the same thing (obviously it was the A/C not cycling not the heating unit). Would this be consistant with your "smart valve" diagnosis or ?

Thanks in advance.


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## #CARRIERMAN

Hi Wolffman

There are many things that cause the problem you are having. Probably the most common for the problem it sounds like you are having is an intermittent limit trip. The major causes of this is either a dirty filter, plugged blower wheel or evaporator coil. The plugged blower wheel and evaporator coil will cause the limits to fail completely if not repaired. This is also a major contributor to early heat exchanger and compressor failure. Unplug your furnace or shut the breaker off to it. Pull the blower compartment door, carefully reach in and feel the vanes of the blower wheel if you pull a bunch of dirt back on your finger. You will need to have the evaporator and blower pulled and cleaned. I am just guessing that this is the problem. If you could give me a little more information I could pinpoint it for you.

Good luck
Rusty


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## Wolffman

#Carrierman thanks for the info.
I have noticed reduced airflow and a whistling like noise also. I replaced the filter ( yes I have neglected to do that on a reg basis like a dummy ) and it seemed to improve but as near as I can recall it is still noiser than previously and noticeably noiser with the filter in.

Any other info that would help on your end just let me know. 
Thanks for the help you have already provided. I am going to check it out tomorrow based on what you have said so far and any further advice.


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## #CARRIERMAN

Wolffman

It's ok, You would be amazed the houses that neglect their equipment. If you have a HVAC company that you like to use, they will need to pump your a/c down and completely remove the evap coil. I personally like to use the foaming condensor coil cleaner to make sure it is spotless. Make sure if they use this method that they thoroughly wash evap out. The condensor cleaner is not intended to be left on the coil. Make sure they completely dismantle the blower assy and wash the wheel good. Make sure they also install a good quality liquid drier and pull a good vacuum on your refrigerant system. If they are a good company, you will be happy with the result.

Good luck
Rusty


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## Wolffman

I should know better. 
Being an automotive technician for 20+ years I am not new to maintaining things and the results when doing so.


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## Jscho

Hello, I am a complete furnace novice, although just had a Heil gas furnace/AC installed this past spring. I have had the same issue with the furnace not "firing up" on a consistent basis. My installer told me the following (please excuse my lay person explanation and I am sure he gave me the "dumbed down" version!)...He said he called tech support and that there is an issue with the burners and the air flow. The recommendation was to replace with a improved burner that addresses the issue. When I asked, he said there is not an actual recall on it. So, he changed my burners and I have had not one problem since. It was very inconsistent before and I would have to reset it with the switch to get it to work. It also did not matter if it was actually off and I turned the heat on or if the thermostat tripped it. So, I cross my fingers that I will no longer have problems since it was a big concern to have a problem so fast!!! I hope this makes some sense for you guys and it is maybe helpful!


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## #CARRIERMAN

Hi jscho

This is not a hard problem to fix, The particular furnace you have should be hot surface ignition. This is a M shaped piece with a porcelin base. What happens to these is depending on the time and day they were built, rather it be 5:00 on friday before the hangover or 8:00 on monday afterwards. Heil has had some problems with ignitor alignment, now your getting ready to become a service tech and not a novice. First locate your ignitor, the M part of the ignitor should be aproximatly 3/8" away from burner. DO NOT TOUCH THE M PART! the oil from your fingers will cause it to hotspot and fail. The second thing you will need to do is make sure that the M part of the ignitor is positioned in front of the fluted part of the burner (this is the little part that looks like a bunch of fingers around the inside of the burner). Remove the metal bracket and ignitor and carefully bend the bracket to achieve the peramiters I gave you. Make sure that when you reposition it that your power is off to the furnace while doing so and that when you are done the M part of the ignitor is not touching any metal. Once you are done, plug your furnace back in and make sure it fires up every time. The reason most technicians tell you they need to call the factory is they have no idea how to fix your problem. Very seldom does any manufacturer allow a piece of equipment to leave the factory in a unoperable state. The repairs are generally minimal.

Good luck, let me know if I can help further.
Rusty


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## Jscho

thanks Rusty.
Hopefully this is what my installer did...as long as I have consistent heat this winter and my house does not blow up, I am happy! And, so far, so good. After reading your post, I remembered that he said something about ignitor alignment so hopefully he figured it out! Thanks again. J


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## Wolffman

Well after reading here I took a couple hrs last Sunday and took a look at my furnace. I looked into all ideas that were posted and found that the sensor that is located beside the ignitor on the pilot tube was carboned up. All I did was clean it up with a peice of emery cloth.
Since then everything has been working A1.
Thanks for the help.


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## Flash-O-Matic

Thanks for the tips everyone. This should help a lot. 

My furnace (Heil DC 90) was also installed brand new in our house in 1999 as part of new construction. I started having issues last winter (of course) just as the temps were hitting the single digits. The furnace would start but wouldn't fire up..then the fan would start and blow cold air into the house. This had happened a few times but, since it was so cold.... To be on the safe side, I called the folks who installed my furnace, and they sent a guy over to take a look at it. 

The guy took it apart, looked inside the combustion chamber, and told me I needed a new heat exchanger. He said it would still be under warranty and all I would have to pay was the labor to put it in. He gave me an estimate of $650 for two hours of work. I told him to stick it and got somebody else in to do the same work for 1/2 the price.

Anyway, the heat exchanger was put in and it didn't help at all. As a matter of fact, it started the same thing the very next day. I was so mad at the the whole ordeal (of trying to find a trustworthy repair shop), I said the heck with it, and decided I would put up with it.

Armed with the information you folks have posted here, maybe I will get it fixed right this time. Thanks.


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## rakes9720

Check the igniter. It should glow orange when the furnace comes on. If not the igniter is broken and needs to be replaced. If it does glow, try cleaning the flame sensor.


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## Flash-O-Matic

rakes...yes, it does glow orange, and there is flame when the furnace first comes on, but then it won't ignite. Just from what people have been posting here, and from you said, I think it has to be the flame sensor. I think that will be my project this weekend...get that cleaned up.

Any tips or tricks for the non-furnace savvy/furnace repair novice attempting this fix?

Also...has anybody heard of any sort of recall or technical service bulletin on this issue? Sounds like a common issue with this year/brand/type of furnace.

Thanks again for everybody's help and advice on this issue.


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## rakes9720

This is a common issue on all furnaces, because after a long time of use, the combusting gas causes an oxide bulid up on the flame sensor. This blocks the current from passing through the sensor, and the furnace does not know if the gas is burning or not. If its not burning, gas will build up, and could explode, so the furnace shuts off the gas to prevent this. A dirty sensor will cause the furnace to shut down even if the burners light.

It is an easy fix, turn off the power to the furnace, remove the sensor rod, and clean it with sandpaper or steel wool, replace the rod, turn on power and test.


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## scameron

I have a problem with my Heil DC90 that is approximately 7 years old. It makes a loud banging noise when the furnace shuts off where you can visible see the back panel of the furnace expand and contract. My service repair person put a brace along the back of the furnace but the problem still exists. The noise is so loud that it wakes me from a sound sleep. The service people at the HVAC company that installed this system are baffeled. Any suggestions?


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## trollmastergeneral

Can you see the duct work expand or due you see the furnace casing move? The usual problem is that the duct work is not crossbroke or the piece is so long it "pops".

A second problem could be that the duct work is to small.


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## Flash-O-Matic

OK...was finally able to get to cleaning the flame sensor on my furnance. Well, actually, I called a friend of mine and he came over and showed me what to do...so he actually cleaned it, but now I know what to do.

Anyway, I am STILL having the same issue. I doesn't happen all the time, but it still happens. There are a couple scenarios:

1). The furnace fires up, the pilot comes on, but gas does not get turned on. Shortly thereafter, the fan kicks on and blows cold air through the house.

2). The furnance fires up, the pilot comes on, gas comes on, flame ignites and, as soon as the fan kicks on, the flame goes out.

3). Everything works fine, the furnace is blowing warm air, then, for no particular reason, the flame goes out.

Anybody have any idea what the heck is going on? Any advice would be greatly appreciated. I'm getting this close to calling up a local furnace company and have them take this piece of  outta here and have a brand new one installed.

Also, anybody know how a person can get ahold of the company that makes the Heil furnace? I would like to call them and/or send them a nice email...and let them know exactly what I think of their furnances and what the chances are of me buying another one (Has something to do with a snowball sitting in a really warm spot).


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## kkf

*Gas not lighting*

I am having a similar problem--can anyone help? The fan comes on for about 1.5 minutes (the air blowing in the house is cold during this time). Then the fan turns off. Next, another (humming?) sound comes from the furnace for ~15 seconds (gas coming on?). A few seconds later, a bright yellow glow is seen in the furnace for a few seconds (HSI lighting), I hear a “click”, then the glow fades away. The humming sound (gas) stops, and nothing more happens. Then I flip the switch to turn power off then on, and the process starts again.

The last time I tried the process, the gas lighted successfully, so the problem is intermittent. Would this indicate a problem with the flame sensor, gas flow, or something else?

If anyone can help, I'll post the solution when the problem is resolved.

Thanks!


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## younggun

I just had the same problem. Last Friday I called for service, my furnace was acting the same way as you are describing. As soon as the technician came in and saw it was a HEIL, he automatically said it would be a cracked Heat Exchanger. He used a snake camera and confirmed that it had a cracked heat exchanger. But that wasnlt the problem, it turned out to be the "SMART VALVE" or gas valve.
However, that's not all.. The technician forced me to change the heat exchanger, as it was the law, once he knew there was a crack, he had to change it.There was a danger of getting Carbon monoxide into the house.The good news is that HEIL replaced the Heat Exchanger for free, but the labor was $900.00(3 hours of labor).
So $1,600.00 later, my furnace is running fine, but I'm still looking into this recall issue. If it's that dangerous, then all the houses in my street must get their furnace heat exchanger replaced($900.00) what a scam....

So in your case, look into replacing the Smart Valve...

Good luck!!!!


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## bernieo

*blowing cold air*

I have a 9 year old heil furnace and about once every 2 days the blower won't turn off. It just blows cold air dispite the t-stat calling for heat. When the power is shut off it resets itself and cycles normally for a day or 2. I changed the flame sensor/glowplug and it is still doing the same thing. Any ideas?
The old style furnaces were more dependable, they would give you 20 years and when they did give up they were easy to fix. Reading these posts make me think there may be a lucrative career oportunity in furnace repairs.


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## younggun

*Blowing Cold air*

You are right, it is incredible how much they charge for HVAC repairs. Your problem does sound like it can be the Heat exchanger unit. Again, it appears that Heil had a recall on these unts and are replacing them free of charge(you pay the labor $900.00), unless you can do it yourself!! I believe there is a law that only certified HVAc technicians are allowed to repair furnaces...Not sure on that.

My advice is to get a professional in to perform a diagnostic test($50-$80 charge) to see what the probem is...

Good Luck


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## Gmrocks

*No flame, no heat*

I just did a search on Heil furnace ignition problems and stumbled across this thread. I previously had issues last winter with this 1.25 year old Heil furnace (model# unknown), which was cold air blowing for seemingly no good reason. When I installed a digital thermostat the problem has seemed to go away for the most part. Now this afternoon I cannot seem to get any life out of the ?#$% thing other than the inducer motor starting up, by the sounds of it. I'm guessing it's an ignitor issue as I see no glowing even after waiting for several minutes, but I'm not sure where it's located to verify and am also very surprised if the ignitor's toast given the newness of the system. Before I pay for an overpriced service on-site call, could I be missing anything obvious here??


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## younggun

*Heil Furnace Problems*

It could well be the igniter. The igniter is inside an enclosure with a small glass window. You should be able to see the flame, which should be a rich blue. Any orange in the flame is signs of trouble. Being that new, I would think the heat exchanger probably is an upgrade. The symptoms you mention seems to point to the igniter, see if there is vaccuum inthe system. You can disconnect the small vaccuum line and place your finger over it. You should get pretty good suction. The problem I had was that the igntier was actually operating as far as turning on the furnace, these was however, no feedback from the igniter to tell the control to heat. 

Good Luck


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## joskel

*heil issues*

I'm having a problem with furnace the thermostat is new and it come on one in a while. When you turn on the heater it would click and then the 2nd click the you hear the furnace come on. Now it the first click doesn't sound the same it doesn't come on with the intensity it used to have and all it does is run without it igniting anything. Any ideas would be welcomed at this polint.


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## bigMikeB

Call a service tech.


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## Mikeee

I would like to add a comment on high efficiency furnaces. Even though you guys are having problems with a certain brand, there are some very good brands that have exellent track records. It is unfortunate that you purchaced one that has had more than its share of problems. 
Do not take lightly advise on a bad heat exchanger though because CO2 leaking into your home can be deadly. I read one comment that eluded to this as being a scam. It was quite disturbing to read this because I have changed out a few of these leaking heat exchangers and it is not an easy job and very time consuming. It is only your safety being considered. If you don't get it fixed or get a new furnace you may just wake up dead! Or at the very least get very sick, head aches, respatory problems etc.
If was me I would bite the bullet a buy a new furnace before I would have one of those problem ones fixed! You put in a new heat exchanger and you still have an old furnace.


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## blueyez

I'm having a similar problem with my furnace... When it goes to cut in to ignite - it clicks and clicks - sounds like the ignitor trying to ignite and it will do this for a long period of time and it won't ignite. Sometimes it helps if we flip the breaker off and leave it for a while, sometimes after we turn the breaker back on, it will start right away. It's been doing this for about a month now and doesn't seem to be getting any better or worse... Any ideas?


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## coach1960

having a problem with my heil furnace myself. it has just started. when i turn the heat on the spark ignitare with spark and light the gas, the burners will burn for about 2 minutes. when the chamber starts to get hot and the sensor tells the fan blower to come on the burners will shut time at the exact time the fan kicks on. they will not run at the same time. when the chamber cools the fan contuies to run and the burners will not relight. tried turning the fan to run all the time then turn the heat on but it will not light with the fan running. any suggestions.


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## witjr_49

*furnace runs but when fan comes on burner goes out*

when the above conditions happen. Have a service tech come out and check your unit out. Most of the time when this happen the heat exchanger is has a crack or a hairline fracture. Danger. The unit could possibly be letting carbon monoxide into you living space. Buy a carbon Monoxide detector plug it in and this will prove if the furnace is unsafe to operate.. this will help if you can't get a tech out quickly. Most new furnaces have a lot of safeties to prevent dangerious situations. A bit of advice

Have a qualified technician check it out!!!!


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## timothyr

I started this thread over two years ago. I still have the same problem. (re-read the first post). I beginning to believe that it is just a flaw with the Heil furnace and replacement parts. Service man is on his way to fix mine again. I'm sure he will be back again next year to replace the ingniter again. And so on, and so on...................


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## JMATT01

I have a Heil DC 90 that was installed in 1996 and just the blower would go on. This was on 12/31 mid afternoon. I called for service. To come over it was $102, ended up being my igniter, that was $140. He was in and out in about 25 minutes, He also oiled the blower, it was making noise. I did watch what hi did and if it happens again it can do it my self. He watched through the little ovel window where the igniter is and said everything looks fine, but I didn't see anything. Am I missing something here. He said I was lucky to get almost 13 years out of the igniter, they usually go out after about 8 years. What about the heat exchanger in this, does it need to be replaced? Should I put a c02 detector next to the furnace, I have one in the bathroom next to my bedroom upstairs. Thanks. I found this site after I had called for service


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## timothyr

Turns out it was the flame rollout sensor was tripped. This occurred due to several factors. THe main factor was my fresh-air intake was frosted over not allowing enough air and the furnace tried to light 3 times before it tripped the rollout sensor. One thing I have noticed is that this only happens whenever we have the fan set to run full time, and the failure only happens in the morning when the thermostat tries to bring the house up to the morning temp setting. I think I am going to have the gas company check the pressure here since we are at the end of a cul-de-sac.


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## woodbuilder

*Heil ultra high efficiency DC90 furnace burner won't light*

When I turn the heat on the exhaust fan runs, the igniter glows orange and the gas valve makes a click sound. However the burner doesn't light and the igniter goes dark after 10-20 seconds. This is all I could observe thru the small peek hole. I removed the pilot igniter unit to get a good look at it. It seems to look OK. Should I try to bend the igniter rod closer to the gas stream? Or should I try to bend the heat sensor closer to the igniter rod? The furnace is about 11 years old and this has happened several times in the past, when it was very cold out, not too long after I bought it. So I'm thankful that it has happened now when summer is almost here. I have until fall to get it working and if I could I would like to avoid having a tech man come out. The blower fan works. I checked it out by turning on the air conditioner. Can anybody help me out here? I will attach a picture of my pilot-igniter unit. Donadb


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## timothyr

It looks like you need to clean the flame sensor rod or replace it. You can usually use a little emery cloth to clean the igniter rod. If you don't feel comfortable doing this, call a service technician.


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## woodbuilder

Thanx Timothyr, I did think to clean the flame sensor rod. Actually I scraped it lightly with the edge of a sharp knife. I will sand, with emery cloth, the igniter rod and re assemble it and give it a go. So, you don't recommend bending the rods? Donaldb


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## kenmac

Does the pilot light ?? When you say burner are you talking about pilot ?? If it's the pilot not lighting. I would replace or try to clean pilot orifice Are you getting gas through that pilot tube when the valve clicks ?? Could also be that dumb valve ( also known as smart valve)


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## woodbuilder

I cleaned off both rods and put it back together but the main burner did not light. Actually I have never seen a pilot flame either but the view is pretty much blocked. Should you be able to see the pilot burning thru the little oval port hole? I did try to put a wire from a paper clip in the pilot gas tube but I don't know it that helped at all. I can't tell if any gas is getting thru the pilot orfice. Once the cover is on you can't see much of anything. Well I must leave for work. Maybe I'll take the unit back out later and check the orfice to see that it is clear. I didn't think to do that when I had the unit out. I guess it could be the smart valve acting up. Anyway thanx for responding. I'll go back to it tomorrow. Donaldb


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## kenmac

Must have pilot gas b-4 burner gas.. Paper clip probably too large for orifice


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## woodbuilder

I took the ignitor-sensor-pilot unit out again to try and clean the orfice out with a fine wire. There doesn't seem to be a hole in the orfice at all, just 3 grooves radiating out from the center of a small (about 1/8") dics. So then used a hand tire pump with a basketball inflater needle blew out the orfice as good as I could. I put it back together and tried it again. It made no difference. The exhaust fan kicks in, the igniter glows orange and there is an audilble "click" but I don't see the pilot lighting. Back to square one . Donaldb


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## kenmac

the orifice is the hole.. It's there. Have you been able to tell if you are getting any gas out of the pilot tube with it disconnected from the pilot ??


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## woodbuilder

I did not turn the heat on while the igniter-sensor-pilot gas feed unit was not mounted by the main burners. How could you tell if gas was coming out other than lighting it? Would you hear it or smell it? How dangerous would it be to turn the heat on with the tube disconnected? Would it be smarter to disconnect the pilot gas feed tube right at the gas valve away from the igniter and sensor? Here again, would you smell the gas or hear it? Donaldb


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## kenmac

donaldb said:


> I did not turn the heat on while the igniter-sensor-pilot gas feed unit was not mounted by the main burners. How could you tell if gas was coming out other than lighting it? Would you hear it or smell it? Would it be smarter to disconnect the pilot gas feed tube right at the gas valve away from the igniter and sensor? Here again, would you smell the gas or hear it? Donaldb


 
Yes ,Yes ,Yes


be ready to kill the power just when you hear the gas come out of the tube at the valve.. It will be a small amount. But , just don't let it blow & blow, Turn it off as soon as you hear it

Of course, the safest way would be to install a gauge at the pilot port.when the pilot valve opens you will see it on the gauge.. You will need a gauge that measures inches of water column gas pressure....be safe however you check it


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## woodbuilder

Thanx, I may try to get a soft plastic tube a foot long or so, that will fit tightly into the opening at the valve where I take the pilot feed tube out of. The gas then would be coming out a foot away from the furnace. I can't imagine an danger that way. And I would be ready to flip the switch. If nothing comes out would that mean I have a bad smart valve? Donaldb


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## kenmac

Well check all your limits, pressure switch, connections at the valve.imop, These valves have had more problems than any other valve on the market


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## woodbuilder

I'm afraid you are talking way over my head. I don't know what you mean by limits, or what a pressure switch is or what a valve.imop is. Thanx for the advice anyhow. I guess I'll have to just break done and call someone. Donaldb


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## kenmac

In my opinion ( imo). added a p any probably shouldn't have....... If you have gas out of the pilot tube . Then it's the pilot orifice. If you don't get gas out of the pilot tube. Checked all the connections at the valve. & don't know how to check the other items.... . You need to call someone


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## woodbuilder

I took off the aluminum tube on the main valve control and stuck a little rubber tube in it and run it to a container of soapy water. When I turned on the furnace and the valve controller clicked there was plenty of gas coming out. So, I guess it has to be the orfice or the igniter. I do see the igniter glow for 10-15 seconds. Unless the igniter has weakened over the last 10 years then it must mean the orfice is plugged up. Is the orfice hard to replace? What holds it in there? I can't see how to get it out. Do you have to buy the whole unit? Donaldb


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## kenmac

If I remember correctly. The orifice spud id stamped steel. It's probably rusted in place. You may tear it up getting it out. If the ignitor is glowing it should light with gas.. You will probably have to buy the pilot assy.


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## woodbuilder

Before I buy an orfice or an assembly I wonder if it is possible that the pilot is burning and that I just can't see it? I see the glow of the igniter but I can't really tell how far down in it is. If it isn't too expensive, I could just go ahead and replace the whole assembly which would include the sensor, ignitor and pilot orfice. Do you know of anyone that handles that assembly. I've been doing some searches but haven't found a good company yet. Donaldb


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## woodbuilder

I can't seem to find a place to buy a igniter, sensor, orfice assembly. Do you know if anyone handles that assembly? Its a Heil DC90 ultra high efficiency furnace. Donaldb


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## kenmac

I did google search & found this place http://www.allpartsgrills.com/productCat99580.ctlg You don't need ignitor if it's glowing... Unless you want a spare


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## woodbuilder

I also had found that site, but the combination set-up looks a little different from mine and it didn't say it would work on a Heil funace. I may give them a call on Tuesday to see if the combo unit will work on my furnace. That sounds like a very good deal. Donaldb


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## kenmac

All the smart valves use the same pilot assy.


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## woodbuilder

Good, I'm glad to hear that. It just seemed odd to me that at a different site I found an igniter alone for about $80! And on this site http://www.allpartsgrills.com/productCat99580.ctlg you get the igniter-pilot-sensor for $34.65. Thats a lot of difference. I will still call them on Tuesday to make sure it will work on my furnace before I order the unit. Thanx kenmac Donaldb


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## woodbuilder

Success! I guess I lucked out. A local heating company guy showed how to get the pilot orfice out. He could not get it out. Apparently it just sets in there but a little rust prevented it from coming out, With liberal shot of WD-40 I gently tapped it on my vise and it fell out. I blew on both ends of the orfice with my mouth and checked it out. There was a pinhole of light shining through. So, I put it back together and it worked! The funny part is after I got it all back together I discovered, in a dark corner of the furnace, a brand new orfice in a smalll plastic bag. Oh well, I'm leaving it in there as long as it works. And now I know I have a new spare orfice if I have that problem again. Thanx for you input kenmac. I appreciated your help. Donaldb


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## kenmac

Make sure that other oricice spud is for the correct gas. It could be for propane or nat gas



by the way,,,,, Good job !


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## woodbuilder

Thanx kenmac, The little plastic bag has 4-5 threaded brass fittings with holes in the cap. I assume it is for the installer to cover all the different models. There is one that looks exactly like my orfice. I really don't know if it a natural gas orfice or a propane orfice. The hole looks a tiny bit larger but it is impossible to tell for sure. There is no literature with them. If I ever go to replace it again, I think I will just go buy a new one. Is the orfice hole for natural gas bigger than for propane? Donaldb


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## kenmac

donaldb said:


> Is the orfice hole for natural gas bigger than for propane?


 


Yes. The nat. gas may be .023 propane may be .015


I don't know what size they may have used for your assy.


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## marykk

Thank you all for the info. I found this chatroom by Googling "Heil furnace heat exchanger".

I also have a Heil DC90 that was installed in my large home about 1999 that has had the Fan set in the ON position to circulate the air (recommended by an HVAC friend but not the installer shortly after installation). In February 2009, the furnace intermittently would NOT automatically heat my home in the mornings after the evening set-back. I would get up and switch the T-stat setting from HEAT to OFF, wait a few seconds, then flip it back to HEAT it would begin blowing heat. After a month or so of this, I broke down and called the company that installed the furnace. The serviceman did his thing about an hour then told me he couldn't find anything wrong, BUT he said there was a "design flaw" problem with the Heil heat exchanger that is covered under warranty. I was relieved, until I talked to someone at their office who explained the "rings" were missing from the heat exchanger and the part(s) are covered under warranty but there would be a $190 charge for the one to two hours of labor. I also asked for their assurance that this would fix the problem, because I would not be happy about another service charge in the fall for the same thing.

I called another older, experienced, retired HVAC guy who told me he didn't understand what "rings" they were talking about and thought they were feeding me a line since it was their slow season and they were probably looking for work for the employees.

Since the heating season has past, I decided to do more research before I part with $190.

Is anyone aware of a Heil recall or reimbursement for this problem?


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## Bernie S.

Same problem, ....my solution..! my furnace would run until the blower fan kicked in. then maybe a minute or two....sometimes longer(but rarely). After reading the posts here i decided to take another look at everything. Turns out i had a dirty trap/clogged drain line. The other day i was checking the pilot system, and kinda just pokin around. I did see water dripping out the tube, so i did not inspect it any further. today i found this thread, and started with the simple advice....Make sure nothing is clogged. I opened the burner panel again and saw two caps on the fitting between the motor and the chimney pipe. When i pulled it off water came out....hmmmmm. i pulled the drain hoses off the chimney stack and the bottom of blower assembly (both run to the same trap). i plugged one and blew hard into the other... it was hard at first , then "pop" free as a bird. It was not plugged totally, but close. when the furnace was between cycles it would drain a lil, but not as it should.....
Water in the fan seems to effect the high switch more than the low, so the furnace would lite,,,run a little while then , "blow out". The fix was instantanious, it ran like normal rite away.

I am no furnace expert, but this was a simple fix.......seems many people have this sort of problem and it is definately worth looking at closely.... ony takes a few minutes..... even if u see a drip of water at the end of the hose.. hope it is this easy for everyone else....thanx for all the posts.


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## nottajake

*Heil DC90 issues*

Well it seems like its been a year since anyone added to this post. I am having similiar problems with my 12 year old DC90. It happened 2 previous times in the past 3 years and I called a service man and both he replaced a "rollout switch", and things seemed to work for a while. Intermittenly, the furnace wouldnt fire up, and I had to power off and reset to get it to fire up.

This time around, I have a bit more time (its not freezing yet) and stumbled across this forum. I am going to try some of the suggestions here by my heroes donaldb, kenmac, and bernie s. 

I am a newbie, but I am going to try 1) testing that gas is coming out of the valve, 2) cleaning the ignitor heads and gas orifice, and look into the drain line issue.

At the moment, I havent looked into any of this to see whats feasible for me, but once I get the cover off, Im hoping everything will make sense. There could be further questions to come!!


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## nottajake

So after I got home from work today, I took off the faceplate covering the pilot light, and unfastened the ignitor and pilot light assembly. I noticed plenty of debris and little burnt metal flakes inside the nozzle of the pilot light/gas outlet. I cleaned that up, and didnt bother with any other testing, as I figured this was 100% the issue. After re-assembling, turning on the gas and power, it fired right up. So far so good! Hope this simple fix works for others too.


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## air_etner

Problem: All I'm currently getting is lots of nice blue spark but no pilot on. I have replaced the spark ignitor I bought at Grainger (see pic) and replaced the stupid 'ol Smart Valve that I bought on ebay. Still, lots of spark but no pilot light on. I checked the pilot line with a rubber hose on one end into a container of water and gas was coming out. By the way, I removed the line and cleaned it out with some brake cleaner and forced air with my air compressor to make sure there was no junk in it. Replaced it and no luck. I was thinking the control board but the fact that gas is coming out to light the pilot should be a good sign. It doesn't make sense to replace it since I can't get that dam pilot on. Are there any sensors in the unit? If so where? I know there is one round one nearby but I hesitate on buying it and just go crazy replacing parts.:confused1: Any suggestions? PLease help.


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## motorfreak

Well it appears that i have the same problem with my Heil product. furnace is about 6-7 years old model ntn3.

The symptom is the furnace turns on via regular trigger, pilot lights, but main burners will intermittently fail to start up. shortly therafter the main blower fan comes on, as if its lit.. but its not and it blows cold air indefinitely until i reset it.Normally in cold weather ( or when its on more much more frequent) it seems to work just fine. Mild mornings and warmer afternoons are when i mostly notice the problem.

When furnace has been sitting for awhile.. Normally i can get the burners to fire if i wait 5 mins with power off. and reset it.. It is very consistent, 100% success getting the main burners to light this way.....for now...... and its fine there after unless the furnace sits dormant for awhile.. 

The other way i can sometimes get it the main burners to fire is to turn the smart valve off with the on/off switch.wait untill the glow happens, flick switch immediately, pilot lights.. and sometimes i will get main burners to fire.this method works about 70% of the time. I notice that i only get one click out of the smart valve when it fails. When it works properly i get 2 clicks. im assuming one relay for pilot valve, and another for main gas valve..

I have replaced my igniter. which didn't change anything one bit(the old one worked perfect, yes i cleaned it) 

Another point to note is the burners burn perfect when my furnace does work as does the pilot. the blowers minor squeeky and there is no sign of condensation or oxidization anywhere on the unit including the orifices.. This furnace has a proper cold air intake ran close by. The thing looks brand friggen new still actually, minus the UN-new issue im having. I keep it clear of dust and blow down the burners with air and vac every season..

Now i did talk to a buddy of mine (gasfitter) and he is a little baffled.. on my problem. I just ordered a smart valve assembly off ebay and im gonna try that.. as it was suggested in this thread and by a few other gasfitter dudes i know that smart valves suck.. and probably my failure.. Just wanted to find out if the dude that started the thread ever got his issue sorted.


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## chipmanii

I read all the posts about this unit. I first checked the pilot gas flow from the smart valve with no flow. Pulled the igniter assembly and found the igniter had a hairline crack at the end of the element. It was 13 yrs old. Replaced that assembly and the unit fired up perfectly.


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## Doc Holliday

Sometimes iginitors, the nitrate hsi ones that glow, have miniscule fractures not visible to the eye. They will light up and glow but the furnace still will not fire. What you do with those is test amp draw. It should pull a consistant amperage rate until the gas valve opens. With one with a crack that apparently is trying to work, the hotter it gets the wider the crack so it gets hot and then the crack opens up, cutting continuity so the ignitor stops just shy of the gas valve opening.

If the amperage drops before the gas valve opens then the ignitor is the problem. 

Just thought I'd add. :thumbsup:


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## how

Hey Doc
I was under the impression that only Lennox used boards that automatically tested for HSI continuity. Do you know of any other brands that do?


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## burgermen

*dc90 furnace blows cold air*

woke up to a cold house. blower still running but no heat. have powered everything down and tried restarting but the only thing that runs is the blower and exhaust blower right away. hear the noise from the pressure sensor. no ignition glow or pilot flame. should the main blower run right away? suspect the smartvalve but would like to check all possabilities.
THANKS.


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## hvac5646

what suspect an open limit i fan is running all the time.

what brand of furnace is it?


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## burgermen

*tempstar dc90 ntgm 100eha3*

thinking the main blower would wait for a delay before running?
its a tempstar dc90 NTGM 100EHA3


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## rahl

My DC 90 has done this for the past 3-4 years. Last year I broke down and had the unit serviced. The first guy that came out determined that it was a faulty thermostat. He placed a jumper between w/r and it fired every time. I replaced the thermostat and it worked for a while and then started doing the same thing. I jumped it again and it worked every time.

So, on to a new service company who replaced the pilot/ignitor. The other option was the gas valve but we started with the cheaper option. Same thing.Still intermittently not lighting. 

My question is why would jumping w/r make it work every time? What does this do? Does this point to a solution in anyone's mind?


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## tribrach

younggun said:


> It could well be the igniter. The igniter is inside an enclosure with a small glass window. You should be able to see the flame, which should be a rich blue. Any orange in the flame is signs of trouble. Being that new, I would think the heat exchanger probably is an upgrade. The symptoms you mention seems to point to the igniter, see if there is vaccuum inthe system. You can disconnect the small vaccuum line and place your finger over it. You should get pretty good suction. The problem I had was that the igntier was actually operating as far as turning on the furnace, these was however, no feedback from the igniter to tell the control to heat.
> 
> Good Luck


There are several reasons that a furnace won't operate properly. Not many of which should be attempted to be repaired by a homeowner. I know everyone here has had a bad experience with service techs but what do you expect when you don't want to pay them. You say that it's not worth it but what value do you attach to your time and health. Get multiple bids on everything from car repairs to doctor diagnosis to HVAC repairs and you will have better results. IF YOU HIRE CRAPPY PEOPLE AT A CRAPPY PRICE YOU WILL GET CRAPPY WORK!


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## tribrach

Jumping Red to White normally bypasses the tstat and tells unit to operate in heat. If the unit comes on repeatedly when you do this then you have a bad tstat. If this is happening multiple times you need to find out what is causing the stat to fry.


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## gulfcoaster

My Heil furnace would not light. You could hear it try but it would never fire up. 5 yr ago a service tech placed a small piece of aluminum tape as a wind block on on the the base of the ignitor. It was only about 2" x 2", he said the small fan that comes on during ignition was moving propane away from the ignitor.

I was having problems today, went up to the attic and watched the furnace try to ignite. The igniter would glow and furnace would try to light and then stop. THe Honeywell SV 9541 (Smart Valve) would flash a code 6 flash + 1 flash showing low gas. Replaced the aluminum tape in better wind shield and it fired right up


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