New Wood Insert Door/Glass Issues

[MEYA103]

Hello,

Brand new to burning wood for heat, and having a blast learning and gleaning from all the experience on this site. I recently had an Osburn Matrix Insert (OB02028) installed and while it has been a pretty good experience so far, I'm in need of some assistance.

Just a couple of data points: 1) I have been burning sufficiently dry cordwood and have had a total of maybe 15-20 fires so far 2) I did thoroughly read the manual multiple times and have been operating the insert in accordance with all guidelines and recommendations 3) I have been bringing the unit up to operating temperature very quickly through sound burning techniques, so there has been minimal smoking/smoldering on startups

I've attached some pictures, but basically the issue I'm looking for help with is this:

• I suspect there could be some air seal issues going on with the door. The upper part of the door glass internal metal surround looks brand new, but the lower half of the sides and the bottom as well as the lower part of the door itself are completely stained black with tar. I also have to clean the glass with stove glass cleaner after nearly every use, as the lower left and right corners of the window get brown stains very quickly

• I did perform the "dollar bill test" around the seal and it was fairly tight around most parts, however it does slip out more easily on the bottom half corners and center in the area where most of the brown staining is occuring. I tried to adjust the door using instructions in the manual and it did seem to tighten the door a bit overall, but not specifically along the bottom where it is needed

Is this normal, or does it indicate that too much air is coming in along the bottom of the door where it shouldn't be? Thank you!

 

[EbS-P]

Two questions. Do you have moisture meter? And have you checked the screws that hold the glass in.

 

[MEYA103]

Thanks for the reply - yes have a moisture meter, fresh cut wood faces typically come in somewhere around 16-18%. Also just checked screws, I was able to get them just a bit tighter but they were all the same and pretty tight...

 

[EbS-P]

Thanks for the reply - yes have a moisture meter, fresh cut wood faces typically come in somewhere around 16-18%. Also just checked screws, I was able to get them just a bit tighter but they were all the same and pretty tight...

Then I don’t think you are getting the fire hot enough the black on the fire bricks is my clue. To really learn your stove you need some way to measure temps. How tall is your liner?


An IR thermometer on the same place each time is good enough. Flue temps are best but that’s harder with inserts. It’s possible.

 

[MEYA103]

I thought the installers said the total liner length is somewhere around 21-22ft, as the unit is in my finished basement partially below grade (split level).

My regular procedure is to bring the stove to about 600-650f (measured w/ IR gun) before dropping the intake to half at which point nice secondary combustion kicks in. I then begin to gradually reduce intake until almost closed. Typically settles for a good amount of time somewhere in the 500s.

These are good questions/tips, but do you think there is any possibility that the lower gasket not being as tight as the rest could be causing air to come in on the bottom/sides causing the issue? Noticed that the marks from the gasket are clearly "lighter" in these spots. Also curious whats up with the staining on the cast iron on the left, right, and bottom...

 

[EbS-P]

I thought the installers said the total liner length is somewhere around 21-22ft, as the unit is in my finished basement partially below grade (split level).

My regular procedure is to bring the stove to about 600-650f (measured w/ IR gun) before dropping the intake to half at which point nice secondary combustion kicks in. I then begin to gradually reduce intake until almost closed. Typically settles for a good amount of time somewhere in the 500s.

These are good questions/tips, but do you think there is any possibility that the lower gasket not being as tight as the rest could be causing air to come in on the bottom/sides causing the issue? Noticed that the marks from the gasket are clearly "lighter" in these spots. Also curious whats up with the staining on the cast iron on the left, right, and bottom...

View attachment 319883

That’s pretty tall. 23’ needed a damper on my basement insert. If you did the $$ bill test and there was some resistance (it doesn’t have to clamp. Just a little pressure as it’s not a pressure trapping seal. (In reality it is it just so small) I am seeing gasket imprint on the front so I’m not really thinking it’s the gasket.
Where are you measuring temps at?

My guess that at 20’ you are over drafting and the air wash air is cooling the glass to much. It’s a guess. What don’t know if the matrix has the same exact design as my 1800i. It’s really similar inside.

Things to try. Top down fire. Close if the air down sooner and a good tight packed load. My kindling is always touching the burn tubes. No need to empty ash but every other week or once a month. The ash will insulate keeping the firebox hotter. Don’t bother cleaning the glass with cleaner you will figure out how to get a good hot fire. And it will clean it self.

I probably have 40 fires on my insert and as a self proclaimed expert at running my other stove I’m still figuring it out. This will season 3 and it hasn’t been lit yet.

Keep at it. Take pic of it loaded up text time and post.

 

[MEYA103]

Thanks so much, been trying some of these things and seem to be making some progress 👌

 

[MEYA103]

Thanks again for all the advice, I put these suggestions into practice and things are going a bit better. I do have the stove consistently running hotter through improved burning practices, but still not sure if it's getting hot enough as the glass still needs to be cleaned after nearly every use.

With the break in cold weather in my area I also took the opportunity to drop the baffle and do a quick inspection, and found an ever growing (can literally hear it raining down every once in a while) pile of flaked-off creosote on top. Is this expected given that maybe I had not been burning hot enough/too smoky initially and will clear itself up, or is it a further pointer to a potential drafting issue?

 

[begreen]

Creosote is caused by the flue gases being cool enough that they condense and build up on the liner walls. The occurs when the flue gases fall below around 250ºF.

Show us a picture of how the stove is loaded before starting the fire.

 

[EbS-P]

I’m still seeing soot on brick, that means not hot enough I see the chimney fire sticks in the background. I’m just guessing that you are not using enough wood to get everything up to temp for a clean burn. This is a cold start load in my stove. 11 splits with kindling. I could have packed it tighter but with space like this there is plenty of air and that makes for a hotter fire.

Did we establish is your liner was insulated??

 

[MEYA103]

Thank you all very much for the help. Based on all of your responses as well as working with SBI/Osburn tech support, I believe the issue at the end of the day is that my liner (about 24' in an exterior chimney) was installed with no insulation.

I tested wood moisture content on three separate fresh split faces, and all are somewhere between +/- 15% - 18%, and have really come a long way in burning technique so I'm getting hot fires much faster now. The overwhelming feedback I'm hearing is that the liner being uninsulated (especially being on an exterior chimney) is leading to incomplete combustion. This would explain the underperformance, dirty glass/firebricks, and alarmingly fast creosote buildup.

The issue is that my terra-cotta lined chimney was too small/tight to install a wrapped liner, so it's increasingly looking like we may need to explore the TherMix/Perlite or equiv option. I have read a lot and know that this comes with a number of drawbacks and challenges but it may be the only option to get this unit performing where it needs to be.

Again I know it's not ideal, but does anyone have experience or suggestion with using this type of insulation?

 

[jaybird396]

The uninsulated liner is not ideal for sure, but I would think that if you keep the air open enough you can keep the fire hot enough to prevent the soot build up inside the stove and on the glass. I would try burning it with the air open a little more than you are currently. Also what kind of wood are you burning? Is it all hardwood? Any chance there is some softwood mixed in? I have the Osburn 3500 insert and I have never had any soot on the firebrick or glass, the fire is always hot enough to prevent any soot from forming in those areas.

The uninsulated liner on an exterior chimney will get more creosote build up and will require more air and a hotter fire to keep it from sooting up but you should still get decent results imo.

 

[MEYA103]

Thank you very much, this is helpful and encouraging - I'll try to get her burning hotter by leaving intake open a bit more. I think there may be some softwood mixed in, not exactly sure as I have it delivered. He told me but I forget.