Wood Stove Glass Cleaning - Constant Sooty Glass

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Wolfetone

Member
Apr 29, 2014
41
MA
Hi guys,

So I eventually went with the F500/Oslo Jotul as my first wood stove. Love it. Hold nice stable temps, havent had it up over 500 yet as it just hasnt got that cold and we had a few nights in the 39-43F range so decided to fire it up!

My question is,
The front glass is always dirty with soot. I have been firing the stove up and once the wood is lit I close the air right down. I think this may be the problem. So my question is, do you let the fire initially come up to 400-600F then close the air down?

Then, when you add new wood and load it up, do you again have to open the vent until that wood lights up good, or is it ok to keep the vent closed as the fire is already at 400+F?

Lastly, I heard cleaning the glass with soot is the best glass cleaner, what do you find is best? And how often do you have to clean your glass? As right now im having to clean it EVERY fire.

When the stove was installed they could only fit a 5 1/2 inch stainless steel liner down my chimney, (old house) so I am hoping that is not the issue here.....and wont be.....the good news is the chimeny is in the center of the house so it has an awesome pull/draft
 
Either your wood is wet or you are cutting down the air too much and too soon. I had the same problem in the beginning. To clean the glass you can use moist rag or paper towel dipped in the ash from your fire box. I use a Rutland spray for wood stove glass.
 
Thanks for the reply!
Definitely not damp wood its very nice dry wood, I think its me cutting the air down too early, is there a temp range when its ok to cut it down to avoid this issue? I read in the manual 400-600F so I will try that, but there was very little on this issue.

On the glass cleaning, ive been using damp papertowels in ash to clean the glass, what is the Rutland spray for if you use the ash/water???
 
Rutland is a brand name. I got it at lowes. You can get paste like consistency but I like the spray better. When you are cutting down the air you do it in stages. First cut to 1/3-1/2. Wait 5-10 minutes cut another 1/4. You don't want the flames to die on you. I cannot tell you at what temp you should start doing it because every stove and chimney setup is different, but I would say 400-450 would be a good start.
 
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So my question is, do you let the fire initially come up to 400-600F then close the air down?
Yes. If you cut the air down too soon, the secondaries may not get a chance to ignite and you can even get back puff problems (happened to us when new). As prezes13 said, cut the air down in stages and feel free to experiment some as every installation is a bit different. Try to keep the secondaries going for best efficiency.
 
Hi,

I wait till the stove top hits 600 deg. That's what the manual for my stove (also a Jotul, but one size down from yours, I think) describes as the high end of the ideal operating range (400-600). Then I reduce the air intake by about half for only 2 or 3 mins.. Then maybe another quarter for just a minute.. Then all the way closed. I've found if I reduce the air before I hit 600, the secondaries don't happen, the fire smoulders a little, and I have to turn the air up again for a while. It took me a couple of months to get into an intuitive relationship with this... And I know it would be different with another stove, but as yours is also a Jotul I figure there may be some similarities.

I know quite a few folk here say they need to turn their air down a little before they hit max ideal temp, because their stoves keep on getting hotter for a while buring secondaries. That hasn't happened with my stove - or maybe it's my wood density (mostly well-seasoned oak and ash). Either way. It will be slightly different for each of us.

For me... Black glass would definitely mean I'm not running the stove hot enough at the start of the burn cycle before turning it down... You mentioned you hadn't burned above 500 yet... That would black the glass for me, unless I was buring a small amount of wood fast, which is what seems to work for me in the shoulder seasons. (Although I'm still a relative 'stove newbie'... Only coming into year2!)

If I'm not looking at the actual stove top temp as a guide for when to turn down, I will for sure not turn down until I see that all of my load is charred on the outside.. This usually happens just around the 600 mark for me.

Then, when you add new wood and load it up, do you again have to open the vent until that wood lights up good, or is it ok to keep the vent closed as the fire is already at 400+F?

It's all about burning in cycles... So,when the stove gets to 400 or below, add lots of wood, open up the secondary air and leave it open till the wood is flaming away, charred, and the stove temp is around 600... Then turn the air down. A cycle begins with adding wood and opening the air ... Then closing off at high temp... Then burning secondaries... Then it dies down,then a new cycle begins. Ive heard others here advise not to load up until the stove is at least as low as 400.

For stove glass cleaning... As has already been said here, dip a wee piece of damp paper in some FINE (so it doesn't scrath the glass) ash and it cleans up the glass perfectly for me.. it hardly needs any ash, just a touch is enough. I don't feel the need to buy anything to do this job... But maybe I would if I didn't wipe the glass every day... If I wipe every day I often don't even need to use any ash, wet paper is often enough to take away just a slight clouding of the glass. If I get any actual brown marks on my glass it's either because some wood got too close to the glass or I wasn't burning right.
 
Last edited:
Hi guys,

So I eventually went with the F500/Oslo Jotul as my first wood stove. Love it. Hold nice stable temps, havent had it up over 500 yet as it just hasnt got that cold and we had a few nights in the 39-43F range so decided to fire it up!

My question is,
The front glass is always dirty with soot. I have been firing the stove up and once the wood is lit I close the air right down. I think this may be the problem. So my question is, do you let the fire initially come up to 400-600F then close the air down?

Then, when you add new wood and load it up, do you again have to open the vent until that wood lights up good, or is it ok to keep the vent closed as the fire is already at 400+F?

Lastly, I heard cleaning the glass with soot is the best glass cleaner, what do you find is best? And how often do you have to clean your glass? As right now im having to clean it EVERY fire.

When the stove was installed they could only fit a 5 1/2 inch stainless steel liner down my chimney, (old house) so I am hoping that is not the issue here.....and wont be.....the good news is the chimeny is in the center of the house so it has an awesome pull/draft
Wolfetone, welcome to the forum! Regarding keeping your glass clean, you will find that it will stay much cleaner when you are burning 24/7. In the shoulder (fall & spring)season, it is difficult to keep the glass clean because you do not have a constant fire. Regarding cleaning the glass, I use a damp paper towel and it cleans the glass just fine. I use ash if there is a difficult place to clean on the glass. Hope this helps!
 
Wolfetone,
I have a Jotul F 600, the next size up from your Oslo, but very similar. I agree with others who have said that you might be burning too cool as far as the soot on the glass is concerned.
However, I disagree with the idea that you have to get the stove up to 600 F to burn clean. With my Jotul F 600 I frequently burn in the 350 - 450 F range and my glass stays relatively clean. Marginal wood will definitely lead to a lot of soot on the glass. As for cleaning, I use some Windex or just water and vinegar in a spray bottle with a paper towel for cleaning. As for frequency - after a half dozen fires or so I notice a light greyish film will start to coat the glass, so I will often clean it then since I like watching the fire so much and it looks better when viewed through clean glass.
 
Try the suggestion to decrease the air incrementally. Get the fire going briskly then close down the air, just to the point where the flames start to get lazy. Let it burn that way for about 5 minutes or until the flame regains some vigor, then close it down a bit more until the flames get lazy again. Repeat until closing it down any more would make the fire smolder. The stovetop temp will be between 400-600F at this point depending on whether this was a cold or warm start and the dryness of the wood being burned.
 
I've had 2 oslo's. You are definitely turning the air down too soon and abruptly. This would happen every time, if I just had to shut it down for some reason it would be dirty. After you reload its important to turn the air back up for a while. This will help a lot. How long has your wood been cut/split/ stacked? Under seasoned wood will play big role in dirty glass as well.
 
The glass on my Drolet EPA stove hardly ever gets sooty. I find that the higher the moisture content of the wood, the easier it is to get sooty. I make sure none of my wood I burn for the entire season is above 15% MC. All of my wood is at 7-12% moisture content for this season. I have already burned about an 1/8th of a cord in the past 3 weeks, yet the glass still looks almost spotless. Stove top temps are stable in the 450-650*F for about 5-6 hours.
 
Hi guys,

So I eventually went with the F500/Oslo Jotul as my first wood stove. Love it. Hold nice stable temps, havent had it up over 500 yet as it just hasnt got that cold and we had a few nights in the 39-43F range so decided to fire it up!

My question is,
The front glass is always dirty with soot. I have been firing the stove up and once the wood is lit I close the air right down. I think this may be the problem. So my question is, do you let the fire initially come up to 400-600F then close the air down?

Then, when you add new wood and load it up, do you again have to open the vent until that wood lights up good, or is it ok to keep the vent closed as the fire is already at 400+F?

Lastly, I heard cleaning the glass with soot is the best glass cleaner, what do you find is best? And how often do you have to clean your glass? As right now im having to clean it EVERY fire.

When the stove was installed they could only fit a 5 1/2 inch stainless steel liner down my chimney, (old house) so I am hoping that is not the issue here.....and wont be.....the good news is the chimeny is in the center of the house so it has an awesome pull/draft
Sounds like your wood is possibly not fully seasoned, or you are burning at too low a temp before allowing the fire to reach a good critical mass and get a solid bed of coals going. Plus, when you clean the glass never spray anything directly on the glass, rather spray the cloth or paper towels, dip in some ash, and wipe away. If you spray directly on the glass whatever cleaner you use invariably will seep into the glass gaskets, and that is a sure way to shorten their lifespan. Just my 2 cents.
 
Wolf tone, based on the way you described your fire starting procedure I would be willing to bet your wood is seasoned, at least good enough to give you clean glass. I would expect any stove I've ever had to fall flat if shut down that way from a cold start in 40 degree weather, yet you are getting steady heat of over 400 degree stove top temps. That's pretty good.

Others above have given good advice on shutting the air down in steps so no need to go into details here.

It's "your" stove and you will find "your" own procedure to get it to cruising temps but just remember to do it in steps and you should have a good, clear view of your fire.
 
I clean my door glass with wet newspaper and ashes from bottom of stove and it cleans like magic. NO NEED to buy stuff to clean the glass.
 
Not much to add that hasn't been said about the wood or turning down the air incrementally and not going too far.

For that matter, not much to add about cleaning the glass . . . 24/7 burning is better . . . wet newspaper or paper towel dipped in ash for the really baked on stuff or just simply damp newspaper for a light coating . . . commercial stuff works as well (but I'm cheap) . . . or you can "burn" it off the next time you have a fire and the secondaries start firing off.
 
I've also had dirty glass the last small fire I had probably because it's not cold enough yet. Small fire and low draft due to outside temps= dirty glass. Try burning a really hot fire as an experiment and see what happens. This probably sounds weird, but I buy the cheapest automotive liquid wax and use that on my glass, both cleans it and helps prevent sticking the next time it gets dirty
 
For non-cat stoves during the shoulder season, short and hot fires work better than longer low temp fires. Also, if you are new to burning epa stoves and you've had multiple days of of dirty glass, make sure that you give your chimney a look before the weather turns cold and icy. If your glass is dirty, imagine what it is doing to the chimney.
 
Hi guys,

So I eventually went with the F500/Oslo Jotul as my first wood stove. Love it. Hold nice stable temps, havent had it up over 500 yet as it just hasnt got that cold and we had a few nights in the 39-43F range so decided to fire it up!

My question is,
The front glass is always dirty with soot. I have been firing the stove up and once the wood is lit I close the air right down. I think this may be the problem. So my question is, do you let the fire initially come up to 400-600F then close the air down?

Then, when you add new wood and load it up, do you again have to open the vent until that wood lights up good, or is it ok to keep the vent closed as the fire is already at 400+F?

Lastly, I heard cleaning the glass with soot is the best glass cleaner, what do you find is best? And how often do you have to clean your glass? As right now im having to clean it EVERY fire.

When the stove was installed they could only fit a 5 1/2 inch stainless steel liner down my chimney, (old house) so I am hoping that is not the issue here.....and wont be.....the good news is the chimeny is in the center of the house so it has an awesome pull/draft
I ue Rutland cream cleaner. This stuff polishes the glass so it become resistant to buildup. Of course using really dry wood or Envi blocks will give you a nice hot and clean fire.
 
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