Creosote burning on low inevitable..............

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MCPO

Minister of Fire
Hearth Supporter
................first time I noticed it. I burned about 15 bags so far this year and all on the lowest (#1) setting. On a recent test last week I got 40 hrs on a bag burning at the lowest setting. The literature says .8 lbs per hr is the lowest but the stove won`t go that low.
Let me say this, at 1 lb per hour the air blowing out isn`t too hot but warm enough to heat my entire finished basement (900) sq ft to 74-77 dgrees in the shoulder seasons of 35-50 degrees outside.
Anyway I did notice the upper right corner end of the heat exchanger had a small amount of creosote on it , not really much but it was there.
I`m sure it will burn off as soon as the weather gets colder and I turn up the volume but the point is these stoves probably aren`t burning at their best when set on a low burn.
I`m neither surprised or dissapointed since my glass does stay clean for days and that upper corner was the only place I can see any creosote.
 
thanks Gio,

I thought creosote was only a thing from wood stoves, not pellet stoves....guess I was wrong...

.
 
I wonder if the low setting, combined with the volume of distribution air is causing condensation on that part of the heat exchanger? For the most part the combustion chamber is hot enough to keep at the creosote forming materials in suspension in the exhaust gases. Gio- do you run the distribution fan somewhere between med-high? Interesting observation regardless.
 
I've got this issue too. But I'm worried b/c the evil stuff is building up above/behind my heat exchange tubes where I can't get at it to scrape it out. How the heck are you supposed to clean up behind them buggers anyway?
j
 
Crank your stove up a few times per week and you'll burn off that creosote before it becomes a problem. I usually crank mine up to 3-4 on my analog board (goes to 6) every morning when in the shower... leave it up for 20 minutes or so.
 
I apologize up front, and forgive my ignorance if so, but can a pellet stove really create true creosote? My thought is that we may be dealing with semi-wet fuel and or cold vent and condensation making a goopy ash mix? My understanding after years of burning wood stoves and now a pellet stove for 6 years is that you need crappy combustion of crappy fuel (i.e. green wood) over time to make true creosote. I have never seen a pellet stove make true creosote, I've seen too many stoves and vents to count, none of which had a true 'creosote' issue. That said, I have seen too wet fuel in biomass stoves condensing in the vent and causing leaky crap which imho is a different issue. Again, correct me if I'm wrong please? Kroos, ya got ice on the lakes yet? Time to go!
 
GotzTheHotz said:
I apologize up front, and forgive my ignorance if so, but can a pellet stove really create true creosote? My thought is that we may be dealing with semi-wet fuel and or cold vent and condensation making a goopy ash mix? My understanding after years of burning wood stoves and now a pellet stove for 6 years is that you need crappy combustion of crappy fuel (i.e. green wood) over time to make true creosote. I have never seen a pellet stove make true creosote, I've seen too many stoves and vents to count, none of which had a true 'creosote' issue. That said, I have seen too wet fuel in biomass stoves condensing in the vent and causing leaky crap which imho is a different issue. Again, correct me if I'm wrong please? Kroos, ya got ice on the lakes yet? Time to go!

I`m gonna have to bet it`s creosote. Oh yeah it`s black and shines like wet tar.
Not that it`s much at all but I think burning pellets at a very low rate like I have been at only 1 lb per hr does create a small amount of creosote that would not normally be there. Actually I did not notice it last year.
I`m not too concerned about it and I surely don`t want to alarm anyone either cause it really doesn`t appear to be a significant issue.
 
I've observed the same thing,and believe it's from just what gio said burning at a low rate stove never really getting hot enough, but since I've seen it I run it on high for 30 min a day and it's all but gone now.
 
a pellet stove will produce creosote. i burned my p38 on low for most of last winter. when i turned it up in the spring i actually had a small chiminey fire. flue was very clean after that but is was scary. the only thing it damaged was the esp probe. now i run it on 2-3 part of the day and turn it off as opposed to running on low all the time.
 
Hmm, guess I'll have to crank her up more often and shut it down more often rather than run on low. I would have been turning it off more, but my wife, the utility bill nazi, pitches a fit if she hears the furnace kick on :)
j
 
Delta-T said:
I wonder if the low setting, combined with the volume of distribution air is causing condensation on that part of the heat exchanger? For the most part the combustion chamber is hot enough to keep at the creosote forming materials in suspension in the exhaust gases. Gio- do you run the distribution fan somewhere between med-high? Interesting observation regardless.

Very good question! And good thinking.
To honest I didn`t run the distrib. fan on high last year when on low burns. This year I did. I will now run that fan on low-med instead and see if it makes a difference.
 
Gio said:
Delta-T said:
I wonder if the low setting, combined with the volume of distribution air is causing condensation on that part of the heat exchanger? For the most part the combustion chamber is hot enough to keep at the creosote forming materials in suspension in the exhaust gases. Gio- do you run the distribution fan somewhere between med-high? Interesting observation regardless.

Very good question! And good thinking.
To honest I didn`t run the distrib. fan on high last year when on low burns. This year I did. I will now run that fan on low-med instead and see if it makes a difference.

Its this "outside the box" thinking that earns me the little bucks. I didn't mention this before but I assume you've been doing your "pellet dance" to appease the mysterious forces at work.
 
I am going to take a stab at this. It does sound like condensation. Call it what you like, but you are not adequately burning the fuel. The area where it is condensing may be a lot cooler that the rest of the burn chamber. It could be at the point where your air wash air comes into the firebox, the initial entry of your air to the heat exchanger cooling the tubes, or a small leak bringing in fresh air. The point is, you are not burning the pellets and are instead making smoke. That does not burn and produce heat in your stove. Adding more combustion air at the current fuel rate, or reducing the feed rate may improve the burn. It is not ideal. Realize minimum output is not the setting the manufacturer intended to set as the optimum efficiency of the stove. While it may seem you are gaining an advantage in slow burning, you may be losing the Btu value out the pipe.

I use shorter burns at higher levels to increase the efficiency, it does cause temp swings, put not significant. I mostly try and avoid using the stove when it gets too tough to regulate.
 
littlesmokey said:
I am going to take a stab at this. It does sound like condensation. Call it what you like, but you are not adequately burning the fuel. The area where it is condensing may be a lot cooler that the rest of the burn chamber. It could be at the point where your air wash air comes into the firebox, the initial entry of your air to the heat exchanger cooling the tubes, or a small leak bringing in fresh air. The point is, you are not burning the pellets and are instead making smoke. That does not burn and produce heat in your stove. Adding more combustion air at the current fuel rate, or reducing the feed rate may improve the burn. It is not ideal. Realize minimum output is not the setting the manufacturer intended to set as the optimum efficiency of the stove. While it may seem you are gaining an advantage in slow burning, you may be losing the Btu value out the pipe.

I use shorter burns at higher levels to increase the efficiency, it does cause temp swings, put not significant. I mostly try and avoid using the stove when it gets too tough to regulate.

Being it`s a manual start stove I have to live with a slow continuous burn vs higher burn and temp swings.
 
geek said:
thanks Gio,

I thought creosote was only a thing from wood stoves, not pellet stoves....guess I was wrong...

.

Pellet stove for sure can build up creosote. Gio is burning a good quality stove, so he isnt (shouldnt)going to have much of a problem. I've seen other pellet stove make enough creosote to cause chimney fires.
 
Gio said:
littlesmokey said:
I am going to take a stab at this. It does sound like condensation. Call it what you like, but you are not adequately burning the fuel. The area where it is condensing may be a lot cooler that the rest of the burn chamber. It could be at the point where your air wash air comes into the firebox, the initial entry of your air to the heat exchanger cooling the tubes, or a small leak bringing in fresh air. The point is, you are not burning the pellets and are instead making smoke. That does not burn and produce heat in your stove. Adding more combustion air at the current fuel rate, or reducing the feed rate may improve the burn. It is not ideal. Realize minimum output is not the setting the manufacturer intended to set as the optimum efficiency of the stove. While it may seem you are gaining an advantage in slow burning, you may be losing the Btu value out the pipe.

I use shorter burns at higher levels to increase the efficiency, it does cause temp swings, put not significant. I mostly try and avoid using the stove when it gets too tough to regulate.

Being it`s a manual start stove I have to live with a slow continuous burn vs higher burn and temp swings.

Mine is a manual also, but it only takes a few seconds to restart. That's why I say I avoid the use as much as possible in the shoulder seasons. I might get a 10 degree swing, but it doesn't bother just me. Two years ago I set the burn to optimize at low settings, but it burned terrible at higher settings.
 
the p38 is not the most handy stove to light. i fill burn pot with pellets and apply a generous amount of gel. the light with door open and comb fan on let it burn for 5 min. then shut door with latch in closed position so it hits the outside of the catch. let burn for 5 min then close door and it will go. sitting at the computer in between. just went through liting process now
 
rickwa said:
the p38 is not the most handy stove to light. i fill burn pot with pellets and apply a generous amount of gel. the light with door open and comb fan on let it burn for 5 min. then shut door with latch in closed position so it hits the outside of the catch. let burn for 5 min then close door and it will go. sitting at the computer in between. just went through liting process now

Got your image. Sounds like the Jamestown. That's the TWEAKIN" stove. It's tempermental too. I cheat the heat with it. I use a firestarter like supercedar. These are high resin chunks from the base of very old pinions. They stick to your fingers at room temp. Start the usual way with a half handful of pellets, gel, and a chunk. Door open, no air get the chunk going. Near close door, wait five, add air, when I get a 4 inch flame, closer her up and it the start cycle. She's a fine old lady and needs a little coxing, but once started she can dance all night. :smirk:

My other stove is not as tempermental and is in the shop where it needs to be cycled during the shoulder seasons. It's manual, but starts light a young filly. I don't heat over night, so it isn't a problem.

If you tweak the air up a little, you should get a cleaner burn. Just remember you are leaning from the bottom, when you increase the cycling it may affect the burn a lot. I adjusted the feed control up a little on the control board so it didn't starve for fuel. I guess you would say I raised the low end by a small factor. I monitored the exhaust for a few days and tried to eliminate any visable smoke during the burn. I had a little more ash, but not appreciable. Texture was a little coarser. If you can't tweak, try running it higher a couple of times a day and live with a little less efficiency, but you should eliminate build up inside.
 
rickwa said:
the p38 is not the most handy stove to light. i fill burn pot with pellets and apply a generous amount of gel. the light with door open and comb fan on let it burn for 5 min. then shut door with latch in closed position so it hits the outside of the catch. let burn for 5 min then close door and it will go. sitting at the computer in between. just went through liting process now

Use up the remainder of that slow starting gel stuff and start using using 91% isopropanol alcohol (IPA) It`s only $2.49 per qt at WalMart. Saturate a cupful of pellets with a couple of Tbs of it and dump em into the *cold* burn pot. Light it and close the door and long before 5 minutes passes you will have your stove blowing hot air. Nothing faster or more dependable from my experience after trying just about everything else.
 
thanks for the tip Gio. my p38 is in the finished basement also. but i have a st croix lancaster upstairs burning corn. that stove is a manual lite also. but it lights like a dream, 1 cup of pellets a little gel, shut the door and start, leave for work. but i cant complain about the P38 it has been burning for 6 years with very little trouble.
 
Thanks for the tip Gio! i just lit the P38 with the 91% alcohol from walmart and it worked great! i have been burning this stove for 6 years and never had it lite this easy
 
Interesting thread. My St Croix burns on low for at least 6 weeks
before I can turn it up to #2 without being cooked out of here
but I've never once seen anything even remotely resembling
creosote in my stove or the vent.
 
each stoves "1" is different. i have a st croix that will burn on 1 for extended periods of time with a very clean burn
 
rickwa said:
Thanks for the tip Gio! i just lit the P38 with the 91% alcohol from walmart and it worked great! i have been burning this stove for 6 years and never had it lite this easy
Glad it`s workng so good for you.
Some folks use different methods that work well for them . This one worked the best for me.
 
Xena said:
Interesting thread. My St Croix burns on low for at least 6 weeks
before I can turn it up to #2 without being cooked out of here
but I've never once seen anything even remotely resembling
creosote in my stove or the vent.

Your stove #1 might not equate to my Harman #1. I can get 40 hrs on a bag. Are you getting that long a burn out of a bag?
 
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