Flue Liner and Stove Pipe

[rawfdawg]

Hello,

I am a novice add-on wood furnace burner. This is the first year I have used it, and I have quickly discovered it is not as simple as just adding wood to a firebox. I bought a house which had a Johnson Energy Systems J-9900 add-on wood furnace. I had a chimney sweep inspect the flue. It turns out the clay tile had a crack. The chimney sweep noticed that the tile was oriented the wrong direction in the chimney. This would complicate the install. The chimney sweep installed a 304 rectangular flex liner. He sealed off the original location, and and put the thimble with the wide side of the liner. Because of this, he did not use black stove pipe as the connector from the wood furnace to the chimney flue. It appears he used a round flexible flue liner as as substitute for black stove pipe.

My concerns are:

1) Is this safe? I am concerned that it may produce toxic fumes? Notably, from nickel and chromium. And secondly, is it acceptable not to use black stove pipe? I have researched installation manuals for 304 liners, but I can't find anything where it specifically states where it can't be used as stove pipe. The thinness of the liner concerns me. And no where can I find flexible black stove pipe. I don't think it exists.

2) Too much draft may be a problem too. When discussing with the chimney sweep prior to installation, I had mentioned that most add-on furnace manuals recommended both a manual and barometric stove pipe dampers. It does not look like there is any way to install one with a flexible liner as a stove pipe. The chimney sweep told me it would not be needed. He stated that the draft could be sufficiently controlled using the flap thermostat assembly and the ash door dampers. But so far, no matter what configuration I attempt to use with the intake dampers, it does not seem like the firebox is getting hot enough. And I have very short burn times. I am new to this, so there is probability it could be user error too.

Back to the primary question at hand: can I use this flexible liner in place of the traditional black stove pipe? I am assuming the chimney sweep did not have any other options. If he had used black stove pipe, it likely would have had too many bends in it to have sufficient draft?

Any feedback or recommendations will be greatly appreciated. I am brand new to the use of wood furnaces. I never imagined how complex it can be. Thanks to the experienced users who share their insights with the less knowledgeable.

rawfdawg

 

[brenndatomu]

Is this safe?

Hi rawf!
Hmm, not sure what to think about this one...it doesn't look too professional, but safe...paging @bholler ...
I don't see why you couldn't put black pipe in there...use as many 45s as you can...limit the 90s. A baro or key damper in there (with a manometer permanently mounted) is very likely needed. Your draft is probably sky high!

 

[bholler]

Well first off he could have kept the crock where it was. It would have meant opening up the hole and using a custom tee but that is what i would have done personally.

As far as the liner being used as stove pipe It is not thick enough to be used as connector pipe I forget the gauge requirement but it is definitely thicker than .006" . But you will not get any fumes off of it. But like you said not really any way to put a damper in there of any sort and it really does look like crap. I am sure you could use rigid black pipe. I would think that 4 elbows most of them being less than 45 would work and the last one at 90 to go into the crock. I don't think that would hurt draft to much.

 

[rawfdawg]

Well first off he could have kept the crock where it was. It would have meant opening up the hole and using a custom tee but that is what i would have done personally.

As far as the liner being used as stove pipe It is not thick enough to be used as connector pipe I forget the gauge requirement but it is definitely thicker than .006" . But you will not get any fumes off of it. But like you said not really any way to put a damper in there of any sort and it really does look like crap. I am sure you could use rigid black pipe. I would think that 4 elbows most of them being less than 45 would work and the last one at 90 to go into the crock. I don't think that would hurt draft to much.

The chimney sweep did have a custom tee made. But when he received it from the manufacturer, he did not think it was up to his quality standards. And he then decided to keep his plan to move the crock. In hindsight, I wished I would have told him just to keep it where it was at. Since the flue pipe/stove pipe is connected directly to the the thimble at the crock, can I install the black stove pipe into the thimble? I guess what I am asking, will a 7" black stove pipe fit into the opening of the thimble? The way it is now, the flue/stove pipe is just tightened around the end of the thimble itself.

I'm glad to know the flue liner does not emit toxic fumes. In a forum post I had read, someone had mentioned flue pipe vaporizes when heated and emits toxic fumes. I researched this, but could not find anything which confirmed this. I found a detailed study on exposure risks of nickel and chromium from stainless steel products. But none of the products were from the inhalation of heated stainless steel fumes. I asked this, because every time I use the wood furnace, I get a continuous headache which lasts till I don't use the wood furnace for a couple days. I did not know if it was just me? But my wife confirmed she got a headache after she was in the basement. I thought it might have been from the flue pipe. There is a carbon monoxide detector. And it does not go off. Possibly, there is a leak in the connection emitting flue gases into the basement?

I

 

[rawfdawg]

Hi rawf!
Hmm, not sure what to think about this one...it doesn't look too professional, but safe...paging @bholler ...
I don't see why you couldn't put black pipe in there...use as many 45s as you can...limit the 90s. A baro or key damper in there (with a manometer permanently mounted) is very likely needed. Your draft is probably sky high!

My suspicion is that it sky high also. I have researched manometers and read many forum posts, but I still have not grasped on how to implement the use of one on this flue pipe serving as a stove pipe. My first step is to get a black stove pipe installed. Then I can go about drilling a hole for the manometer.

 

[brenndatomu]

In a forum post I had read, someone had mentioned flue pipe vaporizes when heated and emits toxic fumes

That is probably galvanized pipe.

I asked this, because every time I use the wood furnace, I get a continuous headache which lasts till I don't use the wood furnace for a couple days. I did not know if it was just me? But my wife confirmed she got a headache after she was in the basement. I thought it might have been from the flue pipe. There is a carbon monoxide detector. And it does not go off. Possibly, there is a leak in the connection emitting flue gases into the basement?

That sure sounds like CO poisoning, better get someone in there with a good tester before you use the wood furnace again. I'd check the furnace out good, could have a crack in the firebox or heat exchanger.

Since the flue pipe/stove pipe is connected directly to the the thimble at the crock, can I install the black stove pipe into the thimble?

Is the flex pipe directly connected to the liner or is it just mortared into the chimney?

My suspicion is that it sky high also. I have researched manometers and read many forum posts, but I still have not grasped on how to implement the use of one on this flue pipe serving as a stove pipe. My first step is to get a black stove pipe installed. Then I can go about drilling a hole for the manometer.

When you get the new pipe installed let me know, I can hook you up with a manometer and how to use it. Its pretty easy really

 

[maple1]

That sure sounds like CO poisoning, better get someone in there with a good tester before you use the wood furnace again. I'd check the furnace out good, could have a crack in the firebox or heat exchanger.

Good idea. Many local fire departments will do this free of charge. Might be worth a call - and might be worth doing before you make any changes so you can rule some things in or out. And likely the sooner the better.

 

[brenndatomu]

Good idea. Many local fire departments will do this free of charge. Might be worth a call - and might be worth doing before you make any changes so you can rule some things in or out. And likely the sooner the better.

Or if you work for a company that has maintenance people that do "confined space entrys", they will have an air monitor that could be used too...if you can borrow high $ tools from work that is...

 

[rawfdawg]

brenndatomu said: Is the flex pipe directly connected to the liner or is it just mortared into the chimney?

I may be getting my terminology mixed up when it comes to thimble/tee. Here is a couple photos. The flex pipe slides over and is tightened. It appears there is two pipes running from the actual tee itself. From the top of the scratch mark is where the rectangle flex liner in the chimney is. I hope this helps.

.

brenndatomu said: "When you get the new pipe installed let me know, I can hook you up with a manometer and how to use it. Its pretty easy really.

That would be great!

 

[rawfdawg]

That sure sounds like CO poisoning, better get someone in there with a good tester before you use the wood furnace again

Could I buy a CO2 meter? Or would a high priced professional grade meter be needed?

 

[rawfdawg]

Good idea. Many local fire departments will do this free of charge. Might be worth a call - and might be worth doing before you make any changes so you can rule some things in or out. And likely the sooner the better.

Thanks for the suggestion. I live out in the county, and my local fire department is volunteer. I'm not sure if they would have a meter? I might have to buy my own or have a HVAC tech come out.

 

[maple1]

Only one way to find out, give 'em a shout.

I don't know for sure, but I think the good ones would cost more to buy than it would be worth to the typical homeowner.

 

[rawfdawg]

I'd check the furnace out good, could have a crack in the firebox or heat exchanger

In order to do this, would I basically have to disassemble the unit, for the most part, in order to clearly see the sides of the firebox and heat exchanger?

 

[brenndatomu]

brenndatomu said: Is the flex pipe directly connected to the liner or is it just mortared into the chimney?

I may be getting my terminology mixed up when it comes to thimble/tee. Here is a couple photos. The flex pipe slides over and is tightened. It appears there is two pipes running from the actual tee itself. From the top of the scratch mark is where the rectangle flex liner in the chimney is. I hope this helps.
View attachment 172337 View attachment 172338 .

brenndatomu said: "When you get the new pipe installed let me know, I can hook you up with a manometer and how to use it. Its pretty easy really.

That would be great!

It sure looks to me like you could attach a 90* elbow right to that. I think you said that is 7"...and the furnace is 6" right? I'd attach with a 7" 90* elbow and then a reducer to 6" the rest of the way to the furnace

I dunno how well it would work for sure, but you can get the home CO detectors that actually have a digital readout on them...may tell you what you need to know

 

[brenndatomu]

In order to do this, would I basically have to disassemble the unit, for the most part, in order to clearly see the sides of the firebox and heat exchanger?

Yeah. It shouldn't be too hard to get the air jacket off...normally. I'm not familiar with that model though

 

[brenndatomu]

brenndatomu said: "When you get the new pipe installed let me know, I can hook you up with a manometer and how to use it. Its pretty easy really.

That would be great!

Just shoot me a PM when you are ready

 

[maple1]

I dunno how well it would work for sure, but you can get the home CO detectors that actually have a digital readout on them...may tell you what you need to know

I was in on another thread somewhere around this joint a year or two ago, about CO detectors. I think the general feeling I got was that those readout ones weren't accurate - and there might be a threshold they had to pass before they would even show any. Meaning there could be CO there even when it didn't register on the detector.

 

[BrotherBart]

The Kidde digital ones have a button you can push at any time to read the current CO level but only alarms above a threshold.

 

[brenndatomu]

In order to do this, would I basically have to disassemble the unit, for the most part, in order to clearly see the sides of the firebox and heat exchanger?

And just FYI, you will want to check things out when the furnace is cold...and then hot too. Some cracks open cold, some hot

 

[bholler]

Any fire dept will have a good co monitor. That tee snout does not stick out far enough. Honestly i would call the guy who installed the liner and tell him he need to come back and extend the tee snout at least 1.5" out of the chimney and then install proper connector pipe. You payed for it to be hooked up right and that is not right. But i agree if you are getting headaches from it everything needs fully inspected and someone with a good co monitor needs to come out when you are burning. I also think that dispute the shortcomings of the residential ones every house that has any appliance that burns anything should have co detectors.

 

[rawfdawg]

It sure looks to me like you could attach a 90* elbow right to that. I think you said that is 7"...and the furnace is 6" right? I'd attach with a 7" 90* elbow and then a reducer to 6" the rest of the way to the furnace

I dunno how well it would work for sure, but you can get the home CO detectors that actually have a digital readout on them...may tell you what you need to know

This model actually has a 7" flue collar on the wood furnace. It predates the current models of similar design, which are now 6". But same difference and still installs as you described. Just use 7" without the reducer.

Great idea on the CO detector with digital readout. I found a low level detector which detects and displays down to 5ppm. Its a bit pricey, but likely worth the cost since it has warnings at lower CO concentrations.

 

[rawfdawg]

Yeah. It shouldn't be too hard to get the air jacket off...normally. I'm not familiar with that model though

Almost identical to the Hot Blast 1500 or 1537. I also saw similar models listed as Clayton and another, sold at Menard's and Tractor Supply. I don't think the Johnson Energy Systems has been in business for quite some time. I know they were around in the 1980's.

 

[rawfdawg]

And just FYI, you will want to check things out when the furnace is cold...and then hot too. Some cracks open cold, some hot

Good tip. Thanks.

 

[rawfdawg]

Any fire dept will have a good co monitor. That tee snout does not stick out far enough. Honestly i would call the guy who installed the liner and tell him he need to come back and extend the tee snout at least 1.5" out of the chimney and then install proper connector pipe. You payed for it to be hooked up right and that is not right. But i agree if you are getting headaches from it everything needs fully inspected and someone with a good co monitor needs to come out when you are burning. I also think that dispute the shortcomings of the residential ones every house that has any appliance that burns anything should have co detectors.

I sent the chimney sweep an email today. I will wait for his response. I can call the fire department. Once I thought about it more, if someone were to have a CO emergency, they would be the one's who would respond. And thus, have a good CO detector. I have a CO alarm in the basement. I read the manual for it, and saw that it alerts after 70ppm for a given time. I plan on upgrading to a low level detector which it's first alert is set at 10ppm for a given time.

 

[maple1]

Would be interesting if you could get a new CO detector before the FD gets there. Then you can get a handle on how accurate it is, maybe, by comparing with what they see. Depending on what they see.