I get this black mark on the glass always at the same spot....lower right. I just cleaned it today and it reappeared on the 1st burn. Why only there and how do I prevent it always happening. Thanks.
![[Hearth.com] Regency stove glass black marks](https://www.hearth.com/talk/data/attachments/309/309148-3784110e551dedfd3d054416af92309b.jpg?hash=XllO4tF_EN "[Hearth.com] Regency stove glass black marks")
Regency stove glass black marks
- Thread starter Williej
- Start date
-
Active since 1995, Hearth.com is THE place on the internet for free information and advice about wood stoves, pellet stoves and other energy saving equipment.
We strive to provide opinions, articles, discussions and history related to Hearth Products and in a more general sense, energy issues.
We promote the EFFICIENT, RESPONSIBLE, CLEAN and SAFE use of all fuels, whether renewable or fossil. -
Super Cedar firestarters 30% discount Use code Hearth2024 Click here
I dislike you strongly. (hate would be too strong of a term)
LOL Im joking of course, but coming from Vermont Castings um, this would be something many strive for and be envious lol.
Do you have any elbows in your stove pipe configuration? Have you checked the gaskets on the door using the dollar bill test?
A leak in an area where the black mark is, could be the culprit.
But there are so many other reasons. Could just be how you are oriented your loads. Be sure to give that glass some space.
Echo Parking Lot
Member
I have an I2500. I get a similar issue if my wood gets too close to the glass. Additionally, I find that the edges of the insert run a bit cooler than the center. Since the Air intake comes from bottom center, the middle gets going fater than the edges. I would make sure the outside pieces are really going before closing the air down and put shorter pieces on the outside if you have them.
The dollar bill test is put a dollar bill between the door gasket and the stove. Close and latch the door.
Pull the bill and notice how much resistance you have. If the bill slides out with no effort, your seal is not as tight as it should be.
That would mean an airleak, cooling down the gases there by introducing cold air (rather than preheated air). This will result in incomplete combustion and creosote deposit right there. Hence brown spots.
Do this in multiple places around the gasket of the door.
Pull the bill and notice how much resistance you have. If the bill slides out with no effort, your seal is not as tight as it should be.
That would mean an airleak, cooling down the gases there by introducing cold air (rather than preheated air). This will result in incomplete combustion and creosote deposit right there. Hence brown spots.
Do this in multiple places around the gasket of the door.
I recently had a CI2700 installed and have the exact same issue. Part of my routine is cleaning the glass every time I burn or every other time. Not a fan of this but I also like to at least start with some clean glass.. My unit is tight and this has happened since day one. Seems to just be something we gotta just deal with.
What is the moisture content of your wood? The wetter the wood, the more incomplete the combustion, and the more crud on your window - and in your chimney.
With a low burn, the air flow over the window from the air wash is going to be less, and will be less able to keep the crud off of your window. But if you are getting crud there, then it's good to check the moisture content of your wood (on a freshly split surface so you're measuring the inside of the split rather than the drier parts on the outside).
I'm burning very dry 4 year old ash. Meter shows 18-20%. Small splits and it burns hot. The black shows on the right and lefty side of my door. Worse on the right.
That (4 yr old) sounds okay, though 4 year old ash generally is quite lower than 18% (at least here, in a humid coastal climate) if it was dried under a non-leaking cover.
If the dollar bill test on the right hand side is okay, then I would think something else is obstructing the air wash flow. Is there a latching mechanism inside the firebox there? (And after that I'm out of ideas, not knowing this particular stove.)
If the dollar bill test on the right hand side is okay, then I would think something else is obstructing the air wash flow. Is there a latching mechanism inside the firebox there? (And after that I'm out of ideas, not knowing this particular stove.)
4 year old ash is generally quite lower than 18% if it was dried without a cover as well.
Same exact thing for me on my Hi500 (Ci2700). More on right side bottom corner than on left side bottom corner. Recently have been burning kiln dried wood 16% and lower. As someone said, it burns cooler on the outer edges, probably because it is wider in the front than the back.
The lower right of my I2500 always gets more buildup. The air intake when the damper is open is in the center, so I think the center gets hotter and the edges smolder longer before they get going. Also the left side is where the door is and I usually have that open a crack when starting up, so the right side always lags a big.
fussen
New Member
I think only choosing a mobile phone plan is more painful than choosing an insert
I'd probably go for the Regency CI 2700 if it weren't for all 'instantaneously' black glass reports. We're replacing a fireplace with full flame view & the last thing I want is to be staring at a black hole in our living room focal point.
We have lots of access to dry wood as we harvest our own, but would want to run an insert 24x7 and do long (low) burns, especially overnight to offset propane costs.
I see the complaints, but has anyone succeeded with the air wash & pleasantly clear fire viewing with dry wood & long low burns?
Thank you...
![[Hearth.com] Regency stove glass black marks](https://www.hearth.com/talk/data/attachments/311/311020-06fb16f62d96e2242673b3007a2f3244.jpg?hash=MtlhQX5rlJ "[Hearth.com] Regency stove glass black marks")
I'd probably go for the Regency CI 2700 if it weren't for all 'instantaneously' black glass reports. We're replacing a fireplace with full flame view & the last thing I want is to be staring at a black hole in our living room focal point.We have lots of access to dry wood as we harvest our own, but would want to run an insert 24x7 and do long (low) burns, especially overnight to offset propane costs.
I see the complaints, but has anyone succeeded with the air wash & pleasantly clear fire viewing with dry wood & long low burns?
Thank you...
Last edited:
I do not know the Regency line.
However, in general, the lower the insert or stove can burn, the more black the glass will be. This is because low burns are in essence smoldering. That creates creosote that deposits on the nearest cold surface, aka the window. Catalysts can still combust that stuff and make it provide some heat (hence the lower, longer burn possible with well-designed cat stoves), but the smoke encounters the window before it sees the catalyst, so there is no way to avoid that.
The one way to avoid that that works a bit, is the second issue: the air wash. The problem is that when you burn low, the fire gets less air. As a result there is not enough air flowing down over the windows to keep the smoke off of them, and it does not work well for the lowest (longest) burns you can do. The air forms a decent sheet in front of the window on burns using more air.
I consider BK cat stoves to be one of the best (i.e. Regency may very well also be one of the best, I don't know) - and BK stoves don't keep their window clean in the lowest burns.
I resolve that easily, however, by burning on high for half an hour to 45 minutes.
Edit: I like your set up!
However, in general, the lower the insert or stove can burn, the more black the glass will be. This is because low burns are in essence smoldering. That creates creosote that deposits on the nearest cold surface, aka the window. Catalysts can still combust that stuff and make it provide some heat (hence the lower, longer burn possible with well-designed cat stoves), but the smoke encounters the window before it sees the catalyst, so there is no way to avoid that.
The one way to avoid that that works a bit, is the second issue: the air wash. The problem is that when you burn low, the fire gets less air. As a result there is not enough air flowing down over the windows to keep the smoke off of them, and it does not work well for the lowest (longest) burns you can do. The air forms a decent sheet in front of the window on burns using more air.
I consider BK cat stoves to be one of the best (i.e. Regency may very well also be one of the best, I don't know) - and BK stoves don't keep their window clean in the lowest burns.
I resolve that easily, however, by burning on high for half an hour to 45 minutes.
Edit: I like your set up!
fussen
New Member
Thanks for this! (And thank you--I'm pretty set on not totally destroying the aesthetic the original owner/builder realized!)
> "I resolve that easily, however, by burning on high for half an hour to 45 minutes."
I take it you mean that this burns off the black, doesn't prevent it? It would be nice to do that in the morning to clear the glass & enjoy flames during the day.
> "The air forms a decent sheet in front of the window on burns using more air."
> "BK stoves don't keep their window clean in the lowest burns."
Based on your BK experience, is there a mid-rate burn that supports the air wash? How long a burn would you get from it with your setup? Maybe we could use that when we're around to see it. (I know, many variables & a loaded question. It's just hard to only work in the absolutes at both ends of the spectrum.)
Really appreciate your time!
fussen
New Member
Thanks for responding!
That makes sense. And I'd be ok with that sacrifice, too, as long as I still got a decently long burn that didn't freeze out the space by morning (some temp drop is ok) and we could enjoy the flames.
May I ask which stove/insert you have? How long can you get at the higher burn rate you use to avoid the rapid creosote buildup?
And that's a good approach in this case!
Yes, it burns it off. If you go low overnight, the home might cool down a bit, and then it would be useful to run high for a bit to warm at least the room back up. Note that I don't know how well this works for the Regency, though airwash is not rocket science and they likely are pretty similar. Maybe @bholler knows? I believe he knows Regencies well.
Yes, at mid-rate only the corners get a bit covered, and the window is mostly clear. Talking about burn times does not make much sense comparing different stoves, because "mid-rate" for my stove might be a very different rate (of consuming the finite amount of fuel in the firebox) as mid-rate for your stove. It of course also depends on the firebox size.
My midrate (as in middle setting on the thermostatic air control) is 16 hrs or so. I do not believe that will be the case for your stove; the heat output in mine will likely be lower per hour than yours at your mid rate.
If burning high for a bit in the morning after a low overnight burn would work for the Regency, I would just set the insert to provide the heat that you need overnight, and then burn the stuff off first thing in the morning.
The main question is whether your need for heat matches the clean-glass range of the stove, and I just don't know.
fussen
New Member
That all makes sense. Thanks for explaining your approach. Now I can try to see if those who know the CI2700 have experienced similar.
Thank you.
I have the I2500. Last night I kept the damper open a bit. Still has some coals and the fan was still blowing at 7:00 am. (filled the box 10 pm ish) I still got some buildup on the glass, but not black and that did not start until my last step down with the damper (I might have gone too far.) I keep the door latch open after a reload until it is really going, then close the latch, After the probe temp gets over 500, then I engage the cat. I try to get the probe to be close to 700 before shutting down on a full load, and then step that down in increments over the next 30 min. And as everyone has said MC will affect that. Even the difference between 14% and 19% will affect the buildup rate. Also, Slightly shorter splits help. My stove takes 16 N/S. This is my first year so I got 16's and 18's (fits 18 E/W). Next year I am going to cut 15 to keep unburned wood further from the glass on reloads/startup. Just my opinion, but I think that will help the airwash.
fussen
New Member
Wow. Such helpful info! Great tips re. shorter splits for N/S stacking. Thank you!
Re. MC, we live in a very dry climate and, if anything, ours winds up too dry for long burns (especially because hardwood is rare here) - often 7-9%, so hopefully that would help with the blackening.
One more question: I understand that long, dampened/low burns with the catalyst will have fewer/low/no flame. But with the catalyst on, do the flames disappear right away or is there a sweet spot before it’s dampened too far when flame can still be enjoyed?
You’ve been a great help. Thank you.
Whether there is flame depends on how much air is fed to the stove. The cat being on or off has no direct influence in that: (in my stove...) I can have flame easily if I just turn it up higher, regardless of whether the cat is engaged.
Now there is a secondary effect that the cat will increase the impedance of the airflow through the stove, and thus *at the same air setting*, engaging the cat will decrease the total flow a bit, which, if one were just above the point of disappearance of the flames, might result in the disappearance of the flame.
Now there is a secondary effect that the cat will increase the impedance of the airflow through the stove, and thus *at the same air setting*, engaging the cat will decrease the total flow a bit, which, if one were just above the point of disappearance of the flames, might result in the disappearance of the flame.
