What am I doing wrong? (thick logs don't keep the fire)

[stoveliker]

It's more of a slow burning cat problem feature and it depends on the stove and how it's run. Our glass is slightly hazy after 15 yrs of service, but still stays clear. It gets cleaned it a few times during the heating season but that's it.

COrrected it for you.
It's not a problem

But then again, I don't care about car looks either as long as it does what it is supposed to do: drive me safely and efficiently.
Cat stove the same: so the window gets a bit black (though I can always still see the "fire"). I don't care as long as it heats my home safely, cleanly, and at a heat output that suits my wishes.

 

[begreen]

We get great pleasure from watching the fire. It's often better than TV, so yes, a problem for us if it gets too gunky. And a problem because it's harder to clean on a stove when badly soted up. Fortunately, it's not a problem with our stove.
(Car resides in the garage. We like to keep it clean, too.)

 

[stoveliker]

I think the cat-stove black window is overblown.

I have ran 30+ hrs on one load until the cat dropped out the active range at which point I reloaded without relighting (i.e. you can't run any lower) and STILL I could see the fire. Sure black areas were there, but it was still enjoyable to watch the stove. Even with no flame, the varying glowing is interesting to watch. (My wife asks me what I'm doing during those hours that I stare into the box... "Reading" ;p )

And running like that for a week it's easy to clean up by simply running a half load at full bore. No scrubbing or other elbow grease needed.

In my view the often mentioned "black box mode" has more to do with the fact that flames are not there and a quick glance suggests nothing is going on. It's never been "can't see the fire or the heap of glowing fuel" - in my stove, at least.

 

[begreen]

Yes, different folks burn differently. Ashful's stays pretty clean too. And a conventional secondary stove can gunk up the stove window too if the wood quality or draft is poor.

 

[yuryk]

Generally that's between 12 and 30 hours depending on the weather (5 F - 40 F)

You mean you reload between 12 or 30 hours? What kind of stove is it? I couldn't get more than 9 hours from my stove, where last 3 were glowing coals... What's the secret?

NExt time do the same you did now - during the day, and look at what comes out of the chimney.

I actually forgot to mention that I did check the chimney with my flashlight several times as I usually do. And there was smoke. The biggest amount of smoke was there during the first hour - I thought it might be due to kindling and newspaper. But during the second hour there also was some smoke, just a bit less. After about 2-3 hours when I checked - I could see the smoke, but barely. Assuming it was nighttime, I figured there's more than I can see, so I was surprised that even with such a dry wood I'm getting smoke from the chimney... If not water that causes it then what is it? I thought, maybe wood was treated with something? What do you guys think?

Our glass is slightly hazy after 15 yrs of service, but still stays clear. It gets cleaned it a few times during the heating season but that's it.

Wow... I'm then in trouble with my OCD - I tend to clean it after every burn! 😂 I am afraid that if I don't - it becomes harder to clean it (like with a cooking stove when something spills).

 

[stoveliker]

You mean you reload between 12 or 30 hours? What kind of stove is it? I couldn't get more than 9 hours from my stove, where last 3 were glowing coals... What's the secret?

Different design, 3 cu ft box. Not sure how large yours is, but the larger the fire box the longer the burn.
And mine can burn at very low heat output (it's a cat stove).

I actually forgot to mention that I did check the chimney with my flashlight several times as I usually do. And there was smoke. The biggest amount of smoke was there during the first hour - I thought it might be due to kindling and newspaper. But during the second hour there also was some smoke, just a bit less. After about 2-3 hours when I checked - I could see the smoke, but barely. Assuming it was nighttime, I figured there's more than I can see, so I was surprised that even with such a dry wood I'm getting smoke from the chimney... If not water that causes it then what is it? I thought, maybe wood was treated with something? What do you guys think?

When it's cold one can get steam, even with very dry wood. (Complete combustion of hydrocarbons gives H2O and CO2, see the steam from car exhausts in cold weather.) However, that's not the case yet in our current season.
It will be smoke. So something is not going as it should.

I (still) think the air was too low for the fuel. Wetter wood needs more air than dry wood. So while a stove can technically decrease the air, it may not be advisable in a particular case.
Or the air was decreased too soon (the sooner you start decreasing the air, the more likely it is one smothers the fire too much leading to smoke).
Also, air setting is one thing. It's mechanical. But it's only a control of what physics does: draft. The chimney drafts and that is what sucks air into the stove for combustion. One can take a fraction of that air (i.e. close the inlet 50% or so), but if the draft is low, the total air you then allow at 50% (or whatever fraction) may be too low.
Current weather means the draft will be low. Likely too low. It's simply too warm outside.
This would be exacerbated if the chimney is short. (As taller chimneys create more draft.)

I would not worry too much yet. Just wait until the first evening of <45 F outside weather and try again.
Don't loose sleep over a stove that isn't operating pefectly when the conditions are such that one should expect it not to operate perfectly...
Yes that means that if things are not right, you'll be working on that while you want the heat, but working on it now when the conditions are not ideal is not going to help you learn (or get a feeling for) how to operate the stove well.

 

[BKVP]

Did we resolve if the OP has a cat or not? If it's a cat model, out gassing the combustor can result in great amounts of opacity.

That is why I suggested a mix of fuels of varying m.c. to validate the smoke on glass and out of stack.

BKVP

 

[stoveliker]

He did not have a cat.

 

[Freyja]

Dear Community!

Looks like my pre-winter drills don't go as smoothly as I thought it would be... I'm a bit concerned, if to be honest.

I would like to share my third burning experience and ask you to please let me know what did I do wrong. Long story short, my issues were:

• mainly I could not maintain the fire even with half open air flow (sometimes even fully open did not help, so I had to open the door and blow through).
• soot on the viewing glass

My main assumption is probably wood was not dry enough. But I took it from a specific stack of the most dry wood I had! Yes, I made a mistake of not checking all the logs with my moisture meter, but that stack had mostly wood of moisture below 24 when I stacked it about a month ago... Anyway, next time will use my meter before loading the stove for sure!

So, here is my detailed report. Outside temperature was about 52F (11C). I went outside and picked up my kindlings with few logs. My plan was to set up a top-bottom fire for the first time. So I put the biggest logs at the bottom and smallest at the top (under some newspaper). Then I lit the newspaper with fully opened flue, air intake and the door. After igniting I left the door crack open and it looked like this:
View attachment 329618

I worried about the secondary tubes a bit, because after about 20 minutes they were a very tiny bit glowing... But I don't know how this can be avoided in a top-down... Do you?

Anyway, it looked good to me and after about 7 minutes I closed the door and the flue, leaving air intake fully open. After about 10 more minutes I closed the air intake to 1/2 and it looked okay at first. So after another 10 minutes I closed it about 25% more. And again it looked okay with blue fire and secondaries working at first, but then after some time the fire started getting less and less until it disappeared, leaving only glowing coals.

I then fully opened air intake, but it dit not help. I closed the flue and opened the door, then after 5 minutes the fire started again. I waited about 5-7 more minutes and closed the door and the flue. At that moment it looked like this:
View attachment 329620
I thought that it's enough for me to shut the air intake for at least half way, which I did. The fire began to dwindle once more, leaving only the right side alight, where some thinner pieces of wood remained:
View attachment 329621
As you see, the left side was done completely for some reason...

After I left it for an hour or so, that thin wood was finished and mostly only glowing coals remained:
View attachment 329622
Heat output was much lower... From here I left it for some time and when came back saw this:
View attachment 329623

Again, this was with 1/2 air intake open. So I opened it fully, but it dod not help. Then I just went to sleep leaving it like this. And in the morning (after about 7 hours) I found the stove barely warm with this inside:
View attachment 329624

And even despite struggling to maintain the fire, there was a lot of soot on the glass:
View attachment 329625

So, it did burn! But why it was so hard to get the fire going? Is it only because the wood might have not been dry enough? OR can it be because the logs were too thick? Or maybe it's my first time top-bottom method? Or something else? If you ask whether or not there was smoke from the flue - I did check it few times. During all the stages there was smoke. Even during that last glowing coals stage there was a steady semi-transparent, but very visible smoke coming out. That might be pointing to the wood condition?

If this is the wood and not my way of doing things, I have another question: is the only way out to burn whole night with open (or almost open) air intake, so that there is fire? I know from another thread that I have to look for the blue fire, but it's not there when the air is rushing in... So I guess I would just be burning much more my first year?

Please share your suggestions! Thank you very much in advance!

P.S.: I have a Lopi Large Flush Wood Fireplace Insert w/o cat with 30ft insulated liner in exterior chimney.

Hi yuryk!
Don't worry things will get easier. I have the same model as you. It was installed last year and I suffered the "newbie blues". Took me awhile to master the air control and learning to "read" the fire.. Perhaps you remember, I could not achieve secondary burns...

It is still too warm on Long Island for my first burn of the season. Went crazy in 2023 doing MC readings on fresh splits, cracking the nearest window to my hearth and still wasn't running hot enough...I left the door ajar for a good 15 minutes before closing during startups.

Every fire is different depending on environmental circumstances and fuel. BG had posted great photos on how to load the box. His tutorials are fantastic. I achieved greater success when using smaller splits in the beginning and built a good bed of coals. Our firebox is tapered so it limits where to put certain sizes.

Hang in there buddy, you are a sharp guy with a beautiful unit and will be warm this winter...The community gives great advice!..Hopefully I will remember everything I learned last year!..LOL...Good Luck with all...

 

[bigealta]

There is a big difference in Black vs. Brown on the door's ceramic glass with secondary (non cat ) stoves.

Black soot where you need ash and damp paper towel to clean it, 95% of the time, means your wood is not seasoned enough and/or your draft is set to low for most of your burn.

Brown, more like dusty soot, that just needs a damp paper towel to wipe it off and easily wipes clean is not really an issue. It's easy to wipe off when you load on cold or cool starts.

Both can burn off with very hot fires with well seasoned wood burned at a draft setting that allows for a strong burn.

Like Begreen i love watching the fire so clean glass it very very important for me. I get light brown "Dust" often and wipe the glass almost every cold start which for me is almost every morning. Takes 30 seconds to get fully clear glass. Usually the "Dust" is only in the corners.

I have a short chimney so am on the edge of specs.

 

[hoot]

"P.S.: I have a Lopi Large Flush Wood Fireplace Insert w/o cat with 30ft insulated liner in exterior chimney."

Which means there is no bypass. Only air control at the bottom.
I agree that at 52 deg outside it's just a little harder to get a good draft. I would leave the door open longer than 7 minutes and build a good coal bed.

 

[hoot]

It's the Lopi Large Flush insert. Lopi started the hybrid cat version a couple of years ago. I just did all the research when I put my new Large Flush in this year.

 

[hoot]

Exactly what I thought! But my stove shows me I'm wrong, because I see no secondaries working, thinking "oh, it must be a clean burn!", but then seeing smoke from the chimney and wondering: "why the heck my secondaries did not burn these remaining gases and particulates?" I lean towards not having the right conditions. Maybe too low of a temperature near them? But the fire was roaring at first... So still trying to figure it out.


No-no, not ever. I share your passion - I loved fire from my childhood: every time I was getting home from the street - I smelled like a bonfire It's just my 3rd fire with this stove and it's my first ever wood stove. Before I only dealt with bonfires and quick fires for preparing glowing coals for things like barbecue, etc. Using a wood stove for heating is totally different - I have to do it efficiently, but make it hot at the same time... So a lot more to learn!


Yes, thank you, I actually tried to follow it! And the link is right there in The Hearth Room - Wood Stoves and Fireplaces forum in sticky threads section. It's called "Starting a fire and running an EPA stove".

Does your stove have one of these?
And how many secondary tubes does it have?

 

[yuryk]

Which means there is no bypass. Only air control at the bottom.

Hm... I do have a bypass (see at the top):

Does your stove have one of these?

Nope, mine does not have a Cat.

And how many secondary tubes does it have?

4, all of them are visible here:

 

[hoot]

No they had a four tube secondary and no cat. Mine is hybrid and only has two tubes.
The bypass is just to help startup draft.

yuryk what does your instructions say about using the bypass without a cat?​

 

[yuryk]

@yuryk what does your instructions say about using the bypass without a cat?

I guess it's very similar to all the other stoves... i.e. use it for starting the fire. Full manual is here if curious.

 

[hoot]

Looks good. Like it says pull the bypass for startup.

 

[bigealta]

If it was mine, after getting used to this stove i'd be pushing to try starting with aggressive starting (lots of kindling) top down set ups and starting with the damper closed. I'd try lighting then closing the door right away. With the goal of heating the secondary burner tubes as fast as possible to burn up as much smoke as possible and get it up to temp very quickly.

It may or may not work, but i'd be trying.

With a 30 ft chimney you should be getting strong draft. But also as an exterior chimney a cold chimney may be a hindrance to easy starting? you'll just have to see after seeing different conditions.

 

[hoot]

If it was mine, after getting used to this stove i'd be pushing to try starting with aggressive starting (lots of kindling) top down set ups and starting with the damper closed. I'd try lighting then closing the door right away. With the goal of heating the secondary burner tubes as fast as possible to burn up as much smoke as possible and get it up to temp very quickly.

It may or may not work, but i'd be trying.

With a 30 ft chimney you should be getting strong draft. But also as an exterior chimney a cold chimney may be a hindrance to easy starting? you'll just have to see after seeing different conditions.

I don't think he has a damper. Inserts typically do not unless you are talking about the bypass.
You aren't trying to heat the secondary tubes themselves. They are simply manifolds to allow outside air in through the holes. The air gets drawn in as the draft increases.

 

[bigealta]

I don't think he has a damper. Inserts typically do not unless you are talking about the bypass.
You aren't trying to heat the secondary tubes themselves. They are simply manifolds to allow outside air in through the holes. The air gets drawn in as the draft increases.

Sorry yes the bypass.
And yes you are trying to heat the tubes and the whole top of the stove.
The secondaries will light off very quickly with the top down set up.

With a bottom up the secondaries don't light up for a much longer time.
There is not enough heat at the tubes to ignite the cool smoke.

 

[hoot]

The top of the stove has a baffle so it doesn't get that hot. The air tubes are attached to the baffle. The only purpose of the tubes is to provide secondary combustion by injecting fresh air. The internal heat of a good fire sends superheated fuel-laden gasses up and mixes with the fresh air coming from the tubes. Sure those tubes will get very hot but it's the fire itself that gives off very hot gases.

 

[bigealta]

The top of the stove has a baffle so it doesn't get that hot. The air tubes are attached to the baffle. The only purpose of the tubes is to provide secondary combustion by injecting fresh air. The internal heat of a good fire sends superheated fuel-laden gasses up and mixes with the fresh air coming from the tubes. Sure those tubes will get very hot but it's the fire itself that gives off very hot gases.

Exactly. The top meaning Baffle and Tubes.
The air path feed for secondary tubes is designed to pre heat the secondary air. The tubes also provide a final huge boost to the preheated air temps.

The primary fire flames at the tubes (with Top down) provide the heat to quickly ignite the super heated gasses with the preheated secondary air.

The superheated primary gasses from Bottom up starts are cooled to much, as they pass up around and thru the larger splits, to light off quickly by the secondary air.

I have posted quite a few videos here of this in action.

 

[hoot]

Exactly. The top meaning Baffle and Tubes.
The air path feed for secondary tubes is designed to pre heat the secondary air. The tubes also provide a final huge boost to the preheated air temps.

The primary fire flames at the tubes (with Top down) provide the heat to quickly ignite the super heated gasses with the preheated secondary air.

The superheated primary gasses from Bottom up starts are cooled to much, as they pass up around and thru the larger splits, to light off quickly by the secondary air.

I have posted quite a few videos here of this in action.

Exactly

 

[yuryk]

try starting with aggressive starting (lots of kindling) top down set ups and starting with the damper closed.

I thought that's what I did in that timelapse video... Is this what you meant? I closed the bypass (air goes around) about 5 minutes after starting the fire.

I have posted quite a few videos here of this in action.

Could you please share few links? Just curious. Thanks!

 

[bigealta]

I thought that's what I did in that timelapse video... Is this what you meant? I closed the bypass (air goes around) about 5 minutes after starting the fire.

Could you please share few links? Just curious. Thanks!

Yes and also just like the very 1st pic you posted.
So with your time lapse you waited 5 minutes to close the bypass, I'd try to push that time as short as possible but 5 minutes isn't bad.

You can speed it up by using even more dry kindling on top and have the middle row of splits be a little thinner, and with more space between the rows of splits by using "Stickers" or "Spacers" placed N/S (front to back" between the rows.

But practice with different setups will guide you to what works best in your stove.

This is the general set up idea.
This particular set up is for longer burning vs faster start. For faster Start i'd use more kindling at the top and 1/2 the size of the splits in the middle row which would probably make room for an additional middle row.

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