Hard black residue on fire pot

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timbo

New Member
Hearth Supporter
Oct 9, 2009
119
Concord area, NH
OK, I'll bite...what is the hard black stuff almost like baked on carbon "something" that accumulates on the inside of my firepot? It's a groan to scrape off when I'm doing my weekly cleaning....Is it pitch from the pellets baking on or is this a normal thing that happens with all pellet stoves. I used to think they were "clinkers" 'cause they kind of look like a coal clinker but have seen here that pellet clinkers are different animals altogether then what I'm seeing here...
 
I don't know what it is actually called, but I refer to it as carbon deposit also. In any case it is normal. I bought a gasket scraper and use it to scrape over the burn pot holes and sides of the pot where it builds up. Then I use a long flat head screwdriver to chip the deposit from the front of the auger and all around the opening. Sometimes you have hit the screwdriver lightly with your hand or a hammer because the deposit can be tough to chip away. Its just part of the beast as they say. I have an o-ring pick that I use to keep the bottom 5 holes clean and open. If those holes get caked with the deposits, you will find that the stove is harder to light.
 
I may be wrong, but think it's creosote. After my first week of burning off and on I never scraped the burn pot. When the stove was cold and I had some time, I decided to do a good vac and cleaning. Found the layer that you are talking about which was tough to clean. Since then, I do a quick scrape of bottom/sides on the burn pot daily. Go right under the burning pellets. Does not hinder anything and the flame will start up again right after you close the dooe. Takes less than a minute with the stove running. Since then, deposits are not building so much and flame is staying much stronger.

Also, again I may be wrong here, but I think that the lower burning at this time of year will create more of this than when in mid winter and higher flame heat, more often.
 
I always called it scale. But as codebum said its just a carbon build up. Heavy mineral deposits.

I am not 100% sure but I believe the clinkers are caused by the amount of chlorides in the fuel. Chloride can cause the ash to stick together. Increasing air helps reduce the clumps. But a fuel with a high chloride level will still clinker even with the proper air ratio. You can burn it lean(blow the pellets out of the burn pot) and still get them if the chlorides are to high. Chlorides are considered as salts.
 
I call it resin and it makes the burn pot door on my Quadra-Fire Castile stick every once in a while. I purchased various Mac scrapers in different bends and lengths. I just make it a point to give it a good scrape daily. If you let it build up it is a groan to remove. Someone else on the board suggested a Dremel and with the right attachment I bet it would work great.
 
hey Groundhog..... last year when I was burning 'Valley Forest' (crap) pellets, I had to use my dremel tool almost once a week with a coarse grinding stone bit, breathing dust mask, mitts and eye protection etc. to grind away the hard buildup so I could get my clean out door to open.... I tried several hand scrapers and couldn't touch it.... I was afraid in all my scraping frenzy that I was going to break the porcelain temp sensor casing on the side of the pot..... the dremel was the ticket..... would manually start the blower (so it would suck the dust outside) then grind for about 10 min. to free up the door. This year, burning lignetics, don't have that problem what so ever....cc.
 
I only have to "scrape" the burnpot in my stove about once per year. I'm going to have the pot coated with a high temp coating for next season similar to what's used on aftermarket automotive exhaust parts. This should keep it cleaner and easier to clean.
 
Once a year??? What are you burning? I'll have to get me some of those! I scrape daily, although I haven't tried to see how long I could go without scraping. Just do it out of habit and fear of ticking off my stove....
 
newf lover said:
Once a year??? What are you burning? I'll have to get me some of those! I scrape daily, although I haven't tried to see how long I could go without scraping. Just do it out of habit and fear of ticking off my stove....
I would have to agree once a year is a bit crazy!!!!
 
I use a wood chisel to scape of the carbon build up in my firepot. I actually do it everytime I clean it. The cleaner you keep your stove the better it will run over time.
 
I scrape every time I clean the stove (about 3 days).

I use a 5-1 tool available at every hardware store.

It takes just a minute to chip off the buildup and clean out the holes.

I do this outside on my back deck railing.

The buildup is worse in the shoulder seasons when the stove is running on low.

---Nailer---
 
Scraping the burn pot is part of owning a pellet stove. Some stoves don't have as much a problem as others. If you vac your stove weekly a twenty second assault with a scraper is all you need. I have a rectangular burn pot so I use a slightly modified 3/4 inch wood chisel. When the air starts getting interferred with I scrape, that's a result of lesser quality pellets not fully burning, also comes with a clinker or two, usually. If you don't scrape your quality will just decline. After some particularily nasty pellets a few years ago, I had to ream out the air holes. They were full of a yellowish crusty stuff, I was told was caused by salt in the wood used to make the pellets.
 
I use a small wire wheel on a die grinder to clean the inside of my burn pot. Easiest wat to clean a circular shaped burn pot.
 
I just cleaned mine. I soak it and my agitator in hot water, then tap the burnpot with the agitator to get all the hard stuff off. Then I use a wire brush to clean them up good. I agree that its worse at low temps and its the worst part of cleaning the stove. Do mine once a week or so. Not really sure what it is, suppose its a baked on carbon deposit. I burned alot of lignetics last year along with several other brands and this year penningtons and I noticed very little difference between pellets as far as the black deposits are concerned. Its the way it is.

Schoondog
 
I scrape my burn plate and auger tube 1-3 times per week. My favorite tool is an angled nail puller tool from a cheap screwdriver set. The tip is sharp for scraping the burn plate and the angled head works the inside of the auger tube. The V of the tip lets me hit the front 'corner' of the auger tube.
 
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