New Clydesdale sooty glass

[Stumpmonkey]

Hello,
I just had a new Hearthstone Clydesdale installed a week ago and there’s a buildup on the inside of the ceramic glass. The instruction manual says it is self cleaning with high temperatures and it will burn off the buildup but no such luck yet. What should I use to clean it or should I just keep burning and give it more time?
After the break in process I’ve ran this unit for 6 days straight and had it nice and hot daily.
Thanks

 

[stovelark]

No stove burns where the glass stays spotless- your Clydesdale looks like she is doing well. The slow buildup around the edges are normal for most stoves/inserts. Rutland's hearth and glass cleaner is a good product to clean and treat the glass. Sounds like the Clydesdale is doing its thing well. Stay warm..

 

[begreen]

Many stoves will keep the glass clean. Our stove's glass is much cleaner than this after a month of 24/7 burning. It looks like the door gasket may not be sealing well at the bottom corners. The sooty look of the gasket on the bottom door latch side of the door is a telltale sign of a poor seal.

Before firing up the stove again, do a dollar bill test to check the door gasket seal. Take a dollar, lay it across the door opening in a spot, and latch the stove door on it. Pull out the dollar. It should be snug and require some effort to pull out. Do this all around the perimeter of the door. If the dollar comes out easily with little resistance, the door gasket is not sealing well at that location. The dealer should correct this.

The glass can be cleaned. When the coals have died down, open the door to let the glass cool. Then clean using a stove glass cleaner, or water on a towel or ball of newspaper. You can dip the towel or newspaper in a bit of ash to scrub off the stubborn soot.

 

[stovelark]

Begreen you're right, some stoves do keep the glass cleaner, my Enviro stays pretty much clean all year, I clean it once at the end of the season, but its not spotless. Steel stoves tend to have a cleaner glass, I don't know if its their design, the firebrick or whatever, but some stoves (the Jotul Castine was notorious for the sides of the glass to dirty up but the center portion stay cleaner) do better than others. I have friends with the Clydesdale, a wonderful heater but the op's glass is typical of what I've seen... what a heavy insert to handle too!

 

[begreen]

I can see how that big door might be harder to seal. Is the sooting peculiar to the new generation Clydesdale? Past images of older, pre-cat Clydesdales seem to show cleaner glass, but maybe the owners just cleaned them frequently.

 

[stovelark]

BG, I would think its more of a cat-added situation, most cat stoves the air flow is slowed to such that air wash is reduced as well, that would lead to a lower operation temperature (having more control over the burn) with the catalyst, which would bring about a bit dirtier glass. As long as the glass does not darken over (like with wet wood or just too low of operating temp) one can still enjoy the fire show.
Stay warm, happy new year to all.

 

[begreen]

That makes sense.
Have a great New Year.

 

[Stumpmonkey]

Thank you to everybody for your input. It still provides a nice viewing area and heats our home pretty effectively. I will definitely try the dollar bill leak test tomorrow.

Happy New Year!

 

[GM80NY]

I replaced my glass and door gaskets. Its not your gaskets. It’s just a byproduct if you’re going to burn at the medium low setting. If you want the glass cleaner you will need to open the air more. The more you open the air. The faster your loads will burn and the less time your loads will last.

As far as cleaning, the longer you wait the easier it will be to clean. Ash and a wet paper towel works totally fine. Especially after a good load that has a bit more air added. Its better if the glass is warm but not so hot you cant hold your hand on it. Check the inside because Ive had the outside feel good enough but when you touch the inside its still fairly hot. You’ll get the hang of it.

 

[GM80NY]

Another thing that keeps the corners dirty is loading only in the center. If you load two splits on each side front to back this will also help cleaning the glass in the corners. I’ve tried this a few times with success.

 

[Stumpmonkey]

So over the last week, I tried the dollar test and the seal is good. I pretty much always load the full width of the burner insert because I have a nice variety in lengths from 10” to 22” firewood. The ceramic glass cleans off fairly easily with a damp towel but it keeps going back to the sooty black tint on the sides. At this point I’m just burning away and I’ll be periodically cleaning the glass in the morning when it has cooled down.

 

[MJSullivan56]

My Clydesdale II sooted up the glass when doing the three break-in fires, looking pretty much the same as yours. However, once I started burning "full" fires (i.e. the temperature was well within in the proper catalytic target range) the glass stayed clear.

 

[Scott from Akron]

I've gotten into a groove of putting a medium pile of smaller 3/4"-2" diameter branch "logs" on the hot coals in the morning and cracking the door to get a good hot flame going. Once it's flaming real nice I close the door, open the air inlet fully, and crank the blower. I make sure the pieces are closer to the front, near the glass. but not touching. Also, not just in the middle area of the glass, but to each side as someone else suggested. Having a flame near the front tends to clear most of the glass but the very corners. The glass has to get up to @650-700 degrees (based on my laser therm) before it's burning off the darker stuff well. By the time the catalyst meter is nearing the top of it's functional range it's clean enough and I can turn down the inlet air. It'll keep coasting to just about the upper limit and then settle back to mid range. It stays fairly clean until evening unless I fill it and kick it down. However, when we're home I like to keep a smaller hotter dancing flame in there and the glass stays pretty clean.

 

[Chaka]

Hi, this is my first post on hearth.com about my first ever wood-burning insert. My wife and I also got a Hearthstone Clydesdale 8492 this winter and we are also noticing sooty glass. People talk about their wood stove glass getting sooty after months of fires... attached is a picture of the glass after a single fire. This does not "burn off" even when we run the insert at the highest temperature on the catalyst probe. Reading this thread, I'm very curious if this is typical for the new Clydesdale (would be disappointing) or potentially a problem with our installation.

Things we've tried that haven't helped:
- Moisture meter shows seasoned wood has moisture content around 10%
- Also tried with store-bought kiln-dried wood and kindling
- Keeping primary air wide open, except to prevent over-firing
- Keeping the catalyst bypass door open until catalyst is up to temperature
- New insert/gasket, takes a good strong tug to pull out a dollar bill

I'm also attaching a diagram of the air wash provided by Hearthstone.

I'll also mention that we have an exterior chimney, and it takes a good 20 minutes for the stove/chimney to heat up enough to draft all the smoke out of the fire box. We did install an insulated chimney liner.

 

[MJSullivan56]

I'm thinking that due to the size of the firebox (wide but shallow), your corners may not be as hot as the center. Have you tried filling the box to the corners? It seems that the front log should/could be 24" while the back log maxes out at 18" or so. How are you stacking this puppy?

 

[mdocod]

Hi, this is my first post on hearth.com about my first ever wood-burning insert. My wife and I also got a Hearthstone Clydesdale 8492 this winter and we are also noticing sooty glass. People talk about their wood stove glass getting sooty after months of fires... attached is a picture of the glass after a single fire. This does not "burn off" even when we run the insert at the highest temperature on the catalyst probe. Reading this thread, I'm very curious if this is typical for the new Clydesdale (would be disappointing) or potentially a problem with our installation.

Things we've tried that haven't helped:
- Moisture meter shows seasoned wood has moisture content around 10%
- Also tried with store-bought kiln-dried wood and kindling
- Keeping primary air wide open, except to prevent over-firing
- Keeping the catalyst bypass door open until catalyst is up to temperature
- New insert/gasket, takes a good strong tug to pull out a dollar bill

I'm also attaching a diagram of the air wash provided by Hearthstone.

I'll also mention that we have an exterior chimney, and it takes a good 20 minutes for the stove/chimney to heat up enough to draft all the smoke out of the fire box. We did install an insulated chimney liner.

View attachment 307642 View attachment 307643

From the 8492 manual:

[Creosote] Prevention: Burn the stove with the primary air control fully open for 35 - 45 minutes daily to burn out creosote deposits from within the stove and the venting system. After reloading with wood, burn the stove with the primary air control fully open for 15 to 20 minutes. This manner of operation ensures early engagement of the secondary combustion system that minimizes creosote buildup in the chimney. If your glass always remains dirty, your operating temperatures are too low or your wood is wet; therefore, there is a higher risk of creosote buildup.

A hot stove is a clean stove.... If you're running with the air control wide open almost all the time but not reaching temps in the firebox high enough to get the glass to clean up, while simultaneously maxing out the cat probe, then something is amiss.
possibilities:
1. Lack of outside air supply? If this stove breaths air from inside the home, it may be working against negative pressure in the home.
2. Catalyst's partially plugged with soot or ash?
3. Insufficient draft effort? Is the BOTTOM of the chimney plugged off? Make sure the only inlet to the chimney system is the stove itself. Is everything installed tight from the stove to the chimney pipe?
4. Chimney cap obstruction / soot / creosote plugged?

A firebox too cold to burn the creosote off the glass, that drives the cat to max temps, is a smoldering fire that is not breathing well enough in the box to support sufficient secondary combustion before the gasses reach the cat.

 

[Scott from Akron]

Hi, this is my first post on hearth.com about my first ever wood-burning insert. My wife and I also got a Hearthstone Clydesdale 8492 this winter and we are also noticing sooty glass. People talk about their wood stove glass getting sooty after months of fires... attached is a picture of the glass after a single fire. This does not "burn off" even when we run the insert at the highest temperature on the catalyst probe. Reading this thread, I'm very curious if this is typical for the new Clydesdale (would be disappointing) or potentially a problem with our installation.

Things we've tried that haven't helped:
- Moisture meter shows seasoned wood has moisture content around 10%
- Also tried with store-bought kiln-dried wood and kindling
- Keeping primary air wide open, except to prevent over-firing
- Keeping the catalyst bypass door open until catalyst is up to temperature
- New insert/gasket, takes a good strong tug to pull out a dollar bill

I'm also attaching a diagram of the air wash provided by Hearthstone.

I'll also mention that we have an exterior chimney, and it takes a good 20 minutes for the stove/chimney to heat up enough to draft all the smoke out of the fire box. We did install an insulated chimney liner.

View attachment 307642 View attachment 307643

I use a digital thermometer and found the glass starts really burning off the soot when it reaches around 700F. The heat is the highest in the middle area and lowest in the corners where you are showing remaining soot. Once the fire is going well, and loaded up a bit, try not keeping the primary wide open so much. Closing it down to 1/4 or 1/3 seems to actually allow more heat to build up front. Mine seems to burn it pretty clean but the lower corners will not clean all the way. Less air movement allows the waves of secondary flames to travel up and hit the glass lower. In the mornings I try to have small logs towards the front lower corners to get a hot flame closer to the areas of the glass that tend to stay cooler.

 

[Chaka]

I wanted to try a few more fires before responding to everyone's suggestions.

MJSullivan56, the wood in the corners does not burn well. The lower primary air intake is kind of like a laser beam that burns everything in the center, but wood in the corners seems to smoke as much as ignite. I did try putting more wood in the corners and it did not solve the problem.

Scott, I tried measuring the glass temperature with an infrared thermometer assuming emissivity of 0.97. The glass gets to 500 F in the hottest, top-center part when the stove is going good and hot. I think it would be difficult to get it to 700 F without overfiring the catalyst. The Hearthstone manual recommends the top of the stove "not routinely" exceed 600 F. Are you burning off soot from a Clydesdale or some other stove/insert?

mdocod, the catalyst and stove are new, and the chimney was just inspected, so nothing is plugged. I may get a borescope and verify the installer put in a block off plate at the bottom of the chimney. If the issue is draft, what other symptoms would I be looking for?

 

[Garbanzo62]

check to see that your wood is not too close to the glass. I find that if I have a longer piece that area soots up first. I have a glass cleaner but recently have just been using damp paper towel. 99% of the time I can get the glass spotless with just that.
I have watched after a reload, the glass get really dirty, then a small spot in the top center clears and it gradually gets bigger. Never cleasnt to the corners, but it speaks to the low operating temp as a contributing factor.