Safety Check

[Berner]

Finished my install a couple of weeks ago and to satisfy my curiosity I cleaned the flue. This is my first wood stove so I'm not sure what exactly I was supposed to find but I thought I would check with the masters to make sure I'm good to go.

The install is a Progress Hybrid, rear exit to an adjustable 90 degree elbow bent to approximately 30 degrees. That ties into a 17' chimney liner depot flex king pro that runs into an exterior masonry chimney. When I disconnected the adjustable elbow there was a black chalk like substance that covered the walls. I put a plastic bag over the opening and taped it so it would stay put.

Up top the chimney cap that used to be stainless steel colored was mostly black. In the flexible liner there was more black chalk like powder that caked the sides of the pipe. Granted I'm new to this but I was surprised to find anything after just two weeks of burning.

Ran the brush up and down for a few minutes then went to inspect. The total was about one ounce of creosote. What makes me worry the most is that it all seemed to collect in the elbow. I'm nervous that as creosote forms in the liner it's all going to collect in the elbow.


I guess my questions are as follows.

1) Is this an acceptable amount of creosote for just two weeks of burning?

2) Should I be worried about a chimney fire? How much creosote does it take to start a fire?

3) Is the 90 degree adjustable elbow ok? I wanted a T connection but they way the fireplace is built it just isn't feasible.


I've got two young ones and I love wood burning but do get nervous about safety.

Thanks in advance for all your help.

 

[begreen]

You are doing fine. That looks perfectly normal for soot build up. Your elbow will work. If you want to make it more bulletproof get a fixed angle 45 degree elbow instead of the adjustable one.

 

[fossil]

Doesn't look to me like you have anything to worry about. A little flaky black creosote is not a problem. The cap will collect flaky stuff because that's the coldest part of your flue. Perfectly normal, and no big deal...unless it gets bad enough to start plugging it up (you didn't mention whether or not it has a screen in it).

But to answer your questions:

1. Yes
2.a No
2.b Lots more than that, and a different, nastier flavor
3. Yeah, it's OK

 

[Berner]

Doesn't look to me like you have anything to worry about. A little flaky black creosote is not a problem. The cap will collect flaky stuff because that's the coldest part of your flue. Perfectly normal, and no big deal...unless it gets bad enough to start plugging it up (you didn't mention whether or not it has a screen in it).

But to answer your questions:

1. Yes
2.a No
2.b Lots more than that, and a different, nastier flavor
3. Yeah, it's OK

Yes the top cap does have a screen on it. It was colored black but not caked on causing any sort of plugging.

What does the "nastier flavor" creosote look like?

How much creosote do you guys have when you clean your chimneys?

 

[Berner]

You are doing fine. That looks perfectly normal for soot build up. Your elbow will work. If you want to make it more bulletproof get a fixed angle 45 degree elbow instead of the adjustable one.

The advantage of the fixed angle 45 degree elbow being it doesn't have any ridges for creosote to build up on? Anyone hear of a custom T job that would fit this application?

 

[fossil]

Here's one Chimney Sweep's summary of the wide, wonderful world of creosote:

http://www.ctsweep.com/blog/top-sweep-stories/creosote-in-your-chimney/

I'd say the single biggest factor is probably how dry your firewood is. After that, there are a bazillion variables.

 

[Berner]

Here's one Chimney Sweep's summary of the wide, wonderful world of creosote:

http://www.ctsweep.com/blog/top-sweep-stories/creosote-in-your-chimney/

I'd say the single biggest factor is probably how dry your firewood is. After that, there are a bazillion variables.

That is a great article.

"The way to end up with the easiest creosote to clean is to burn seasoned wood in an environment in which there is plenty of air, so that the flue is warmed by the fire’s heat."

Does this apply to an EPA stove like the progress hybrid with a CAT where a low and slow burn is common?

When I get ready for an overnight burn I toss some big splits in char it for 10 or 15 minutes then cut the air down to nothing. It has enough coals and its hot enough that the secondaries fire even with no air but is this not a safe burn because it creates more creosote?

I'm confident that my wood is sufficient. It's been split stacked and top covered for two years now. I was a little worried because the stack is up against a stockade fence (minimal airflow) and it doesn't see much sun. However when I resplit and test the inside I'm consistently down to 15%. It's only cherry, ash and maple so far. We will see if that stays true when I hit the oak.

 

[Nick Mystic]

Since you say you can't get a T-connector to fit your set up and have to use the 45 elbow perhaps you can figure out a way to visually inspect the inside of the elbow without disconnecting it from your stove. You show a Progress Hybrid in your signature so I'm assuming that is the stove you have hooked up to this flue arrangement. I'm not familiar first hand with the inner workings of this stove, but on my Jotul F600 for instance I can lift the cover off the top with two bolts if I needed to inspect the inside of my T-connector. If you can get a view at your elbow somehow from inside the stove, even if you have to use a mirror, you could put your mind at ease by checking it occasionally. It that's not possible maybe you can snake a vacuum cleaner hose up into the elbow area from inside the stove and just suck out any build up when you have some down periods and a cool stove.

 

[Berner]

Since you say you can't get a T-connector to fit your set up and have to use the 45 elbow perhaps you can figure out a way to visually inspect the inside of the elbow without disconnecting it from your stove. You show a Progress Hybrid in your signature so I'm assuming that is the stove you have hooked up to this flue arrangement. I'm not familiar first hand with the inner workings of this stove, but on my Jotul F600 for instance I can lift the cover off the top with two bolts if I needed to inspect the inside of my T-connector. If you can get a view at your elbow somehow from inside the stove, even if you have to use a mirror, you could put your mind at ease by checking it occasionally. It that's not possible maybe you can snake a vacuum cleaner hose up into the elbow area from inside the stove and just suck out any build up when you have some down periods and a cool stove.[/quotgap.

I've got to stop trying to post these on my phone at work...

That's a good idea and there is a small gap.

Actually taking that elbow on and off is the biggest pain of the whole process. I'm second guessing the install a little. I made the connection and then shoved the liner down from the top. My thought here was to give the liner extra encouragement to stay seated in the stove. I wasn't impressed with the three screws that were given for this. When fully seated they are not under tension, they just spin and spin with no bite.

This shoving it down from the top once connected actually leaves the whole system under a lot of downward pressure making disconnecting and reconnecting the 45 degree elbow extremely difficult.

A vacuum and mirror combination is a good idea. It might even save me from disconnecting it at all. I could probably sweep it all down to the elbow and then vacuum it out. Would this be ok? The less moving parts the better but I should probably be taking it off anyways to clean the actual elbow?

 

[Boiler74]

That is a great article.

"The way to end up with the easiest creosote to clean is to burn seasoned wood in an environment in which there is plenty of air, so that the flue is warmed by the fire’s heat."

Does this apply to an EPA stove like the progress hybrid with a CAT where a low and slow burn is common?

When I get ready for an overnight burn I toss some big splits in char it for 10 or 15 minutes then cut the air down to nothing. It has enough coals and its hot enough that the secondaries fire even with no air but is this not a safe burn because it creates more creosote?

I'm confident that my wood is sufficient. It's been split stacked and top covered for two years now. I was a little worried because the stack is up against a stockade fence (minimal airflow) and it doesn't see much sun. However when I resplit and test the inside I'm consistently down to 15%. It's only cherry, ash and maple so far. We will see if that stays true when I hit the oak.

If you lift the cooktop you can see into the rear vent pipe. Hard to clean, but you can see with a flashlight. So check it when you check the CAT.

As for burning, when you throw the big splits in for a night burn, your temps should get up to 400 degrees or so. That's plenty to keep the draft moving and creosote down. The burning I did last year with dry pine created very little soot. One thing to learn is the amount of heat depends on the amount of wood. Fill the firebox full and the heat will climb higher during the low CAT burn than if you only put in a few splits. So stock it up for the long night burns and it will stay hot a long time and burn clean. That article was probably written before EPA CAT stove came around

 

[Backwoods Savage]

That is a great article.

"The way to end up with the easiest creosote to clean is to burn seasoned wood in an environment in which there is plenty of air, so that the flue is warmed by the fire’s heat."

Does this apply to an EPA stove like the progress hybrid with a CAT where a low and slow burn is common?

When I get ready for an overnight burn I toss some big splits in char it for 10 or 15 minutes then cut the air down to nothing. It has enough coals and its hot enough that the secondaries fire even with no air but is this not a safe burn because it creates more creosote?

I'm confident that my wood is sufficient. It's been split stacked and top covered for two years now. I was a little worried because the stack is up against a stockade fence (minimal airflow) and it doesn't see much sun. However when I resplit and test the inside I'm consistently down to 15%. It's only cherry, ash and maple so far. We will see if that stays true when I hit the oak.

Berner, it is good that you are thinking about this but do not over-think it.

Drying the wood 2 years as you have should give you some great firewood. That black stuff may have came in when you did the burn-in. You did do a burn-in with this stove, I hope? Because there is such a great quantity of soapstone, it can soak up a lot of moisture and this is the reason for the burn-in along with curing the paint and other parts.

Yes, what was said about burning seasoned wood with plenty of air does still count. However, with the stove you have, you will give it less air but still do just fine. That stove is designed to burn super clean and it will. I still question shutting the air off but others have done so. I still would prefer to give it just a little bit of air; not much, maybe even 1/4" open but some air. Of course it does still get some air when the draft is closed but it is minimal. All epa stoves are designed so you can not totally cut off the air. But now consider what was stated: "The way to end up with the easiest creosote to clean is to burn seasoned wood in an environment in which there is plenty of air, so that the flue is warmed by the fire’s heat." So, by setting the draft to zero, are you giving it plenty of air? Again, I say not much, but some.

 

[Boiler74]

If you look at the air fins in the back of your stove you will see that it doesn't cut the air off completely. Notches in the fins allow air to always flow. There is also a small air hole in front if the stove. So you never cut the air off, even with the air turned all the way down. If I ran with the air 1/4 open the stove would burn too hot and not long enough. I know a lot shoot for very light secondary action at the top of the firebox. You might try that.

 

[Backwoods Savage]

If you would please re-read my post you will find that I did not recommend running the draft at 1/4 open. I am well aware of how the stove gets the air that is required by the epa regulations.

 

[Berner]

Since you say you can't get a T-connector to fit your set up and have to use the 45 elbow perhaps you can figure out a way to visually inspect the inside of the elbow without disconnecting it from your stove. You show a Progress Hybrid in your signature so I'm assuming that is the stove you have hooked up to this flue arrangement. I'm not familiar first hand with the inner workings of this stove, but on my Jotul F600 for instance I can lift the cover off the top with two bolts if I needed to inspect the inside of my T-connector. If you can get a view at your elbow somehow from inside the stove, even if you have to use a mirror, you could put your mind at ease by checking it occasionally. It that's not possible maybe you can snake a vacuum cleaner hose up into the elbow area from inside the stove and just suck out any build up when you have some down periods and a cool stove.

I've got to stop trying to post these on my phone at work...

That's a good idea and there is a small gap.

Actually taking that elbow on and off is the biggest pain of the whole process. I'm second guessing the install a little. I made the connection and then shoved the liner down from the top. My thought here was to give the liner extra encouragement to stay seated in the stove. I wasn't impressed with the three screws that were given for this. When fully seated they are not under tension, they just spin and spin with no bite.

This shoving it down from the top once connected actually leaves the whole system under a lot of downward pressure making disconnecting and reconnecting the 45 degree elbow extremely difficult.

A vacuum and mirror combination is a good idea. It might even save me from disconnecting it at all. I could probably sweep it all down to the elbow and then vacuum it out. Would this be ok? The less moving parts the better but I should probably be taking it off anyways to clean the actual elbow?

 

[Berner]

If you lift the cooktop you can see into the rear vent pipe. Hard to clean, but you can see with a flashlight. So check it when you check the CAT.

As for burning, when you throw the big splits in for a night burn, your temps should get up to 400 degrees or so. That's plenty to keep the draft moving and creosote down. The burning I did last year with dry pine created very little soot. One thing to learn is the amount of heat depends on the amount of wood. Fill the firebox full and the heat will climb higher during the low CAT burn than if you only put in a few splits. So stock it up for the long night burns and it will stay hot a long time and burn clean. That article was probably written before EPA CAT stove came around

I do stock it up for the overnight burn but I get nervous about the runaway stove. During these first few months I'm trying to experiment and learn. Once I have it dialed in and my wood gets closer towards three years seasoned I'm sure I'll feel more comfortable loading it to the gills. So far I find it much easier to hit the sweet spot where I don't have to worry about it running away or going out with a 2/3 full firebox.

 

[Boiler74]

If you would please re-read my post you will find that I did not recommend running the draft at 1/4 open. I am well aware of how the stove gets the air that is required by the epa regulations.

Backwoods, I meant no disrespect. I know you are a wise and knowledgable burner. I've learned a lot from your posts alone. But perhaps you missed a word? Your post says "not much, maybe even 1/4 open..." I read that as suggesting running a 1/4 open. I wanted to chime in with my experience running the PH. That is all. And I was trying to show Berner aspects of his new stove with regards to the air fins; that wasn't directed at you. Sorry if you took any of that wrong.

 

[Boiler74]

I do stock it up for the overnight burn but I get nervous about the runaway stove. During these first few months I'm trying to experiment and learn. Once I have it dialed in and my wood gets closer towards three years seasoned I'm sure I'll feel more comfortable loading it to the gills. So far I find it much easier to hit the sweet spot where I don't have to worry about it running away or going out with a 2/3 full firebox.

You'll get the feel of it. This stove is very controllable with good air control. And seasoned wood will only get you hotter fires. Maybe run it harder when you're going to be home all day, and gradually put more wood in. Will help you learn it's characteristics and feel more comfortable.

 

[Berner]

Berner, it is good that you are thinking about this but do not over-think it.

Drying the wood 2 years as you have should give you some great firewood. That black stuff may have came in when you did the burn-in. You did do a burn-in with this stove, I hope? Because there is such a great quantity of soapstone, it can soak up a lot of moisture and this is the reason for the burn-in along with curing the paint and other parts.

Yes, what was said about burning seasoned wood with plenty of air does still count. However, with the stove you have, you will give it less air but still do just fine. That stove is designed to burn super clean and it will. I still question shutting the air off but others have done so. I still would prefer to give it just a little bit of air; not much, maybe even 1/4" open but some air. Of course it does still get some air when the draft is closed but it is minimal. All epa stoves are designed so you can not totally cut off the air. But now consider what was stated: "The way to end up with the easiest creosote to clean is to burn seasoned wood in an environment in which there is plenty of air, so that the flue is warmed by the fire’s heat." So, by setting the draft to zero, are you giving it plenty of air? Again, I say not much, but some.

I did a few break in fires. I was surprised by the lack of detail in the manual and even when I called woodstock they said only two fires would be necessary. The first one you should aim for a stove top temperature of 250 leaving both the air and bypass wide open. The second break in you should aim for 500 closing the bypass at 250 and cutting the air down in stages to peak the stove at 500.

With this being my first stove and not knowing how it would all react I did a bunch of break in fires. The first went up to 150 with air and bypass remaining open for the duration. The second was up to 250 with they bypass and air remaining open for the duration again. The third I peaked the stove at 400 closing the bypass at 250 and tempering the air down a little at a time. The fourth fire I brought to 500 again closing the bypass at 250 and tempering the air down a little at a time. After that I decided I was good to go but honestly I haven't had the stove much over the 525 mark. First off my house is only 1750 square feet and it is pretty warm in here. Second even with a strong fire it comes up to 500ish and I don't want to give it more air. I'm sure its designed to go higher but I get a little nervous with how much turbulence is present at 500 and don't feel comfortable yet giving it more air.

Maybe my thermometer isn't reading true and my 500 is really others 600 but when I checked it against my IR gun it was pretty close. Interestingly enough there is a large range of surface temps on the top of the stove depending on where the IR gun is checking. Just on either side of the surface thermometer is close to a 60 degree difference. This is when the surface thermometer is placed exactly over the "GR" in "Progress"

On the air/creosote side. I feel as if the sweet spot for the overnight burn is when the stove has reached a temp of roughly 450-500 and the wood has been loaded for 30 mins or so. Here is where I can cut the air completely and the secondaries kick in and fire almost exclusively. There is no flame present below and you can barely see the coals because the air that is introduced is so minimal they don't want to glow. However there is enough smoke and heat for the secondaries to fire and burn the wood on a long slow overnight burn. This may be way off and completely wrong but so far this is what has maximized my burn times. It also might be maximizing my creosote?

 

[Boiler74]

To me that burn is ideal. You're burning off a lot of the nastiness that causes creosote, and turning it into heat.

Read this:

https://www.hearth.com/econtent/index.php/articles/creosote_from_wood_burning_causes_and_solutions

From that article:

"There are only two ways to prevent creosote formation in chimneys. You can either keep the chimney above 250 degree F all the way out the top or, you can burn up the gases that form the creosote in the stove before they reach the chimney. Modern stoves do the latter and capture the heat produced by essentially burning the smoke.. This is true of stoves with catalytic converters and non-cat stoves that burn gases by recirculating them. Either way, less smoke means less creosote. Burn the smoke and you burn the gases. No gases, no creosote. As simple as that."

 

[Berner]

To me that burn is ideal. You're burning off a lot of the nastiness that causes creosote, and turning it into heat.

Read this:

https://www.hearth.com/econtent/index.php/articles/creosote_from_wood_burning_causes_and_solutions

From that article:

"There are only two ways to prevent creosote formation in chimneys. You can either keep the chimney above 250 degree F all the way out the top or, you can burn up the gases that form the creosote in the stove before they reach the chimney. Modern stoves do the latter and capture the heat produced by essentially burning the smoke.. This is true of stoves with catalytic converters and non-cat stoves that burn gases by recirculating them. Either way, less smoke means less creosote. Burn the smoke and you burn the gases. No gases, no creosote. As simple as that."

Thats another good article. Sadly I've been doing most of my burning when I get home from work and its dark out. The next few weekends are busy with holiday parties but hopefully I will have some time off around the end of the year to see the smoke exiting the chimney and examine.

Some white smoke is normal as you close the bypass correct?

 

[Boiler74]

When I first started I thought anything coming out of the flue was smoke. Realized after some reading that you may also see water vapor. Like seeing your breath on a cold day. So if it's white and disappates quickly, it's probably water vapor. It's the same thing you see coming out of a gas fired furnaces flue on a cold day. Try an experiment next time you observe the white smoke.... Open the bypass and observe the change to smoke.