Am I doing something wrong(black glass)

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ymurf

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Jan 8, 2012
151
Missouri
I have only had my quadrafire 7100 going for a few days. I fill it at night and at 5 in the morning I still have some coals to start another fire..But when I turn damper lever way down at night, Usually about 1/4 open, By morning the glass is so black you cant see in anymore.Am I turning it down to low or is this the price you pay so slow the burn down?
 
Can't say on the quad 7100 but both my stoves have a brown glass film after overnight slow burn. And film will be in different places on glass. Never so black not to see through. A HOT fire takes care of it. Many factors affect it: draft, wood placement, temp when shut air down.
 
I'm having some issues with my Napoleon NZ3000 ZC fireplace as well (it's alot like the Quad 7100). I know for a fact that my wood is dry and seasoned (seasoned three years, top covered since early summer), same wood burns fine in my Napoleon 1900p with no black glass at all, even on a slow, lazy burn. I try that same, lazy burn in the NZ 3000 and the glass gets black, every single time.....no creosote in the chimney or on the chimney cap, just black glass. I am thinking that my doors need adjusted as they seem to be sucking some air in (right in the middle where the doors meet), when they suck air in around the doors that nullifies the air wash for the glass (the air wash is a bunch of little holes at the top of the door where draft air comes into the stove, and washes down over the glass), that air is supposed to move over the glass which in turn doesn't allow any condensation on the glass, which in turn means clean glass. Anyway, look and see if your doors are sealing tightly. Do the 'dollar bill' test (take a dollar bill, close it in the door gasket. If it stays in tight, your gasket is tight. If it pulls out easily, your gasket isn't tight enough). you may be having the same issue that I am.......leaking door gaskets and not enough air wash coming down across the glass to prevent condensation.
 
Usually one of the following.
1. Less than dry wood.
2. Cut back the air too soon.
3. Not burning hot enough.
Or combo of all 3. Which is very possible when #1 is the main issue.

Leaky door gasket is usually indicated by a certain area of the glass being dark or black.
Usually the bottom corners.
 
Usually one of the following.
1. Less than dry wood.
2. Cut back the air too soon.
3. Not burning hot enough.
Or combo of all 3. Which is very possible when #1 is the main issue.

Leaky door gasket is usually indicated by a certain area of the glass being dark or black.
Usually the bottom corners.
On these zero clearance fireplace stoves with the twin doors (like the Quad 7100 and the NZ3000), I see a less-than-ideal seal on the gasket where the two doors come together.....and that totally nullifies the air wash on the doors. When that happens, the WHOLE WINDOW gets black as there is no air coming down across the doors.....and believe me, my wood is bone dry.

It even happened with the scraps from the mantel I put up (which is a 160yr old hand-hewn beam that has been indoors for YEARS). I put those scraps in there the other night and it STILL got some black glass. I'm convinced it's not sealing good enough.

I did a test with lit matches along the center seam......draft through that gasket sucked the flame out every time..

I honestly love this fireplace but Napoleon did a piss poor job with the center gasket on this stove. The gasket isn't even touching metal in the center. And there is no pressure ridge on the non-gasketed door to push against the gasket. Just a poor design IMO. I'm not sure how the quad seals along the center...
 
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Ah the double door disease.
I guess that is one of the pitfalls to some fireplaces.
Shame to have the glass get crapped up like that. But at least your getting heat.
 
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Sorry about your troubles Scotty, as I agree they CAN make a double door seal if they design it right. For all their issues the double door is one of the things VC got right.... The gasket seats against a ridge and will seal tight enough to rip a dollar even in between the doors.

Good luck sorting it! Can you go up a size in gasket or try the high density stuff?
 
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I'm having some issues with my Napoleon NZ3000 ZC fireplace as well (it's alot like the Quad 7100). I know for a fact that my wood is dry and seasoned (seasoned three years, top covered since early summer), same wood burns fine in my Napoleon 1900p with no black glass at all, even on a slow, lazy burn. I try that same, lazy burn in the NZ 3000 and the glass gets black, every single time.....no creosote in the chimney or on the chimney cap, just black glass. I am thinking that my doors need adjusted as they seem to be sucking some air in (right in the middle where the doors meet), when they suck air in around the doors that nullifies the air wash for the glass (the air wash is a bunch of little holes at the top of the door where draft air comes into the stove, and washes down over the glass), that air is supposed to move over the glass which in turn doesn't allow any condensation on the glass, which in turn means clean glass. Anyway, look and see if your doors are sealing tightly. Do the 'dollar bill' test (take a dollar bill, close it in the door gasket. If it stays in tight, your gasket is tight. If it pulls out easily, your gasket isn't tight enough). you may be having the same issue that I am.......leaking door gaskets and not enough air wash coming down across the glass to prevent condensation.

You're probably onto something with your specific unit regarding the air wash. Also in general I think leaking air coming in around the glass is cool and causes condensation where it comes in. Pretty sure most units pre-warm air before it enters the stove. Leaking air is cold and escapes the intended pre-warm design.
 
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Sorry about your troubles Scotty, as I agree they CAN make a double door seal if they design it right. For all their issues the double door is one of the things VC got right.... The gasket seats against a ridge and will seal tight enough to rip a dollar even in between the doors.

Good luck sorting it! Can you go up a size in gasket or try the high density stuff?
I'm gonna try one gasket diameter size bigger and see if it helps. If not, I'm popping the glass out of the non-seal door, tack welding a 'ridge' onto the lip that goes over the other door's gasket, and re-installing the glass. Sounds like a lot of work but I have the tools and know-how to do it, it shouldn't be too bad. Worse part of the job will be re-installing the glass in the door while trying to re-use the old gasket.....

Hopefully the thicker gasket will do the trick. I'm going to talk to the dealer that sold me the stove and see if he has anybody else having this seal problem.....
 
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I am guessing most of my problem is the wood. Its been down for a year and a half but was just sawed up and split a couple months ago. I hope to be ready with good seasoned wood next year.Just have to make do with what I have this year.Glass only gets black on overnight slow burn.
 
Ymurf, I always get black glass with my 7100 on overnight burns when the air is cut back. My wood is all about 15 percent mc. Scotty is probably onto something with the air wash.
 
I am guessing most of my problem is the wood. Its been down for a year and a half but was just sawed up and split a couple months ago. I hope to be ready with good seasoned wood next year.Just have to make do with what I have this year.Glass only gets black on overnight slow burn.

Ding ding ding. We have a winner.


That wood is wet. I just cut and split some ash a couple weeks ago that's been on the ground since Irene. It was so wet it was almost dripping.
 
My insert tended to have black glass when new. Although the chunks I was burning weren't the driest, when the insert got a little more seasoned it didn't do that. Again, maybe it's the newness of the unit, in some way.
 
I am guessing most of my problem is the wood. Its been down for a year and a half but was just sawed up and split a couple months ago. I hope to be ready with good seasoned wood next year.Just have to make do with what I have this year.Glass only gets black on overnight slow burn.
I'd say you nailed your problem if the wood has only seasoned a couple months. In my case, the wood is definitely not the problem. I did a 'lit match' test on the center seal and WOW is that thing leaking air. Almost puts the match out! So I may be doing the modification on that door this weekend....I want this thing up to snuff before we open that room up here in mid-January.
 
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I am guessing most of my problem is the wood. Its been down for a year and a half but was just sawed up and split a couple months ago. I hope to be ready with good seasoned wood next year.Just have to make do with what I have this year.Glass only gets black on overnight slow burn.


When I read the first post in this thread I was guessing wood simply because you have not been burning wood that long. You can find many other posts on this forum where people have had the same problem then in another year or two they are amazed at the difference in the stove when you feed it some really great dry wood.

That wood that has been down 1 1/2 years will still be too high moisture. Do not count drying time until it has been split and stacked out on the wind.

This again, is just one of the reasons I recommend everyone has a 3 year wood supply on hand and always burn the oldest wood. You will find when you get to this point that most of your problems (wood stove related) disappear and you will also find you will burn less wood to get more heat. Until then, you will have some battles on your hands. So, staring now, I suggest that you really do need to have all of next year's wood on hand and that means already split and stacked out in the wind.
 
What Backwoods says is very true.

But what surprised me once though was burning some pine boards up that had been laying around here for like 20 years..man did they burn..I mean hot..real hot.
Seems like I could only cut the air all the way and do the cat run or just add a little more air then it was like the gates of hell.

Thing is even that very seasoned pine smoked my glass on low burn.
I'm guessing from the wood out gassing so fast.
 
I have a quad Isle Royale which has double doors. Try the dollar bill test...insert a dollar bill in between the doors and try to pull it out. if it comes out easily the seal is bad, it should be stuck in there pretty good.
We wipe our glass down with each load, just a quick paper towel swipe and it keeps it pretty clean. Each morning we use soft scrub to wipe down the doors and then make sure we wipe it all off with a damp paper towel, we are able to keep it all clean in just a few minutes per day.
 
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Does the glass have to be cooled down when using a damp towel? Could the glass break?
We do it in the AM when it is cool. I would not do it hot.
 
Does the glass have to be cooled down when using a damp towel? Could the glass break?

The glass will not break. It isn't glass, it is ceramic, and just recently someone posted a quote from the manufacturer that basically said "at 1400F you can drop it in cold water".. I have wiped my glass down with a damp paper towel when it was hot enough to make the towel steam and then smolder. I don't do that regularly.. because the timing of getting rid of the paper towel just before you get set on fire is pretty crucial, and my reflexes are not what the used to be.. lol. but it has been done.
 
It seems as though you already have narrowed down the issue, but I'll throw another idea out there.. Are/were you using any type of glass cleaner to help aid in getting the black off the glass??
I had been having the same issue with my glass since I started buring 2 yrs ago. I was having to spray down the glass with a fireplace approved cleaner almost daily because it would get so bad. I had always attributed it to poor wood quality even thought I could acheive hot fires, but most of the wood I burn is cut/split and dumped in a pile late March through May and then I'm burning it the following fall/winter. So not well seasoned for sure
Well one night earlier this season, after reading several times about dipping a towel in ash and rubbing the glass, I decided to give it a try. It's been almost 2 months since I first did that and have only cleaned the glass maybe 3 or 4 other times, mostly shortly after I first did it.. I haven't clean my glass is probably almost a month now. There is a very light haze on it, that's it
My best guess why? I think the cleaner was leaving residue behind that was actually attracting creosote/condensation and making it worse!
 
I have been using glass cleaner and dipping paper towel damp with it in ash and cleaning that way.But some days its really time consuming to get them clean.
 
Burning 15 yr old locust and 5 yr old cherry ( 16-18% moisture) and have smoked windows after every burn with the air turned way down.

So, 15 year old wood. What does that mean? It was cut 15 years ago? Been laying in the woods since? What really counts is the time after that wood is cut to firewood length and then split. After splitting then it needs to be stacked out in the wind to dry. Before splitting, that wood drys very little. Folks tend to see the ends of the logs cracking and think it is really dry. All those little cracks mean is it has dried some on the ends. The center will be much different.

I have some wood right now that was cut to length 10 years ago and if I told you that wood was super dry and ready to burn, I would be telling a lie. I will guarantee that wood is not ready to burn. It might be in another year but I probably won't burn it for 2 more years at least. Also you no doubt know that it takes different amounts of time for drying depending upon the type of wood. The 10 year old wood we have is white oak.
 
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