Bad pellets and creosote?

[stillersnut]

Yes it is now summer, but never too late for pellet talk. I just did my stove tear down and super clean. I had really bad experience with Turman pellets, returned one ton that had 3 inch long pellets, my other ton did not burn "Turman" hot and caused black sticky build up in stove. After hours of scrubing w/ wire brush I did get inside clean. I then decided to clean pipe. The black sticky stuff was in pipe and ruined my brush. Any idea how I can get my stove pipe clean again? How clean should it be? Am I worrying too much? I am just afraid of a fire in the pipe next season when I burn. Any info would be appreciated.

 

[imacman]

I seem to remember you having a thread a few months ago asking about the same problem...the black residue. IMO, it's a lack of combustion air....the stove is running way too "rich" in the air/fuel mixture......very similar to a car that's running with not enough air....you'll get a black tailpipe.

Increasing the air would be the first thing I'd do, and next would be to make sure that the ENTIRE stove is squeaky clean, especially the entire combustion air path. Have you called Jay Thelin and run this problem by him?

 

[stillersnut]

I did play with air adjustments and thought I'd had good combustion. Hammers, Penn, Awf, all burnt awesome. So I thought it was just bad batch of Turmans. I will call Jay and ask. How clean should the pipe be? I did brush but there is still some black sticky residue. Will it burn off after a couple of fires? Thanks, Mac.

 

[summit]

should have no sticky residue.... either you are not getting things clean during normal heating season cleanings, or like imac said, there is too rich a burn going on. If you scrub everything out, run her good and hot for a couple hrs, then clean right after, the residue should remove. There is an underlying issue here, somewhere, that should be addressed.

 

[Fsappo]

I dont think pellet exhaust will burn off creosote. If you can remove all the venting, I would buy some Anti creostote spray, build a fire in a bucket, rig up a way to hold the pipe over the fire and spray about 50 pumps into the fire and into the pipe while burning. Or whatever you need to do. Heat from a fire is what starts the liquid catalyst in the spray. It should dry all that stuff off and the pipe should come clean.

 

[imacman]

I did play with air adjustments and thought I'd had good combustion. Hammers, Penn, Awf, all burnt awesome. So I thought it was just bad batch of Turmans. I will call Jay and ask. How clean should the pipe be? I did brush but there is still some black sticky residue. Will it burn off after a couple of fires? Thanks, Mac.

So you're saying that ONLY the Turmans made the black residue, or has this happened before with other pellets? The post you made about this problem a few months ago....was that in reference to the Turmans also, or was that with other pellet brand(s) too?

As for cleaning the pipe, yes, that needs to be clean, for sure, but I think what everyone above is saying is that the ENTIRE path of combustion air needs to be checked. Now, I have no idea of the internal layout of a Thelin stove, but in general all pellet stoves are pretty similar.

All of the following need to be either brushed & vacuumed clean, or both: air inlet (OAK?), combustion blower removed & cleaned, all ash traps behind firebox, firebox itself, burnpot, etc, etc. And then, if your set-up allows for it, a good leaf blower final clean.

I'm sure other members will be interested in Jay Thelin's thoughts/solutions to this....please post them.

Oh, and yes, I think that a couple of hours with a HOT (read that as the stove set on High heat) will burn off most of that stuff.

 

[stillersnut]

I did talk to Jay today. He said that since the problem seems to only be with Turmans it could be pellet issue, however, he looked up the build year of my stove. In his expert opinion, he said that his stoves don't normally have this issue unless combustion is an issue. He said it was time for new bushings in fan, but I should soon replace the whole fan(which is what I decided). A fan wearing down is not creating the best combustion for efficient burn. I asked jay if I buy a fan from local dealer and he said "only if ya want to pay double the price". He sold me one factory direct, & shipped it today, what a great guy! Any recommends on a creosot cleaning spray so I may clean rest of pipe? Thanks for all the info and help!

 

[jimmie ray]

When you replace the fan, check out the buildup on the fan blades. I've seen that most are very clogged, which will affect the combustion airflow tremendously. Your new fan will soon become the same, unless you determine the cause. If this buildup is considered normal, then you need to clean the blades more frequently. Do you have to remove the fan to thoroughly clean the blades and housing, on this model?

 

[kinsmanstoves]

Sorry Pete but creosote is caused by to much air. The air in turn cools the gases to much and that causes the creosote. Check your stove for leaks or a blocked chimney and try other pellets.

Eric

*****I meant by to much air that it does create incomplete combustion and thus in turn make the creosote. I hope this helps my case*****

 

[Lousyweather]

not wanting to cause a pi$$ing match here, but normally creosote is a product of incomplete combustion. Much of the tar, which is caused during pyrolysis, isnt burned out, usually due to lack of air or low fire temp, ends up getting pushed out the exhaust, and condenses on the cooler portions of the exhaust path. But, Eric has a point, in that the creosote does get deposited in the cooler areas, such as the pipe......heck, Ive even seen it in the firebox........

 

[smoke show]

normally creosote is a product of incomplete combustion. creosote does get deposited in the cooler areas, such as the pipe.

X2

 

[Pellet-King]

Last fall i had smoke smell problems, i had cleaned my stove late in oct and it was fine before i did my annual cleaning, i was pulling my hair out for days trying to figure the smell out, well i finally did the "leafblower" trick but only did it from the pipe up thru the chimney cause i cant get up on my roof too easy, well i watched from outside as my buddy hit the switch and watched black chunks fly everywere out the pipe all over my roof etc...
I never before had a pipe till the top of my chinmey, just used to just have a 6' stainless flex pipe with a blockoff plate at the damper and there's a slight bend as it's not a straight shot up it had creosote buildup i couldnt believe it as i only ever saw dry dust in my exhaust!

 

[smwilliamson]

normally creosote is a product of incomplete combustion. creosote does get deposited in the cooler areas, such as the pipe.

X2

X3


I'm not too familiar with your stove....is there any possible way air is getting into the stove other than from under the burn pot. I've seen pedestal stoves with loose bases do this rather quickly. Leaking gaskets and such in combination with low heat settings can build creosote quite easily. It's advisable to burn any stove on high for at least 1 hr once a week to burn off the onset of any build up. Once it is there it is harder to do. Warm soapy water should remove gummy creosote. Cake-like wafer creosote is a bit tougher. Hope this helps.

 

[SmokeyTheBear]

Well let's see about that folks,

Is there anyway that too much air (in effect) can cause incomplete combustion?

Yes, if the air isn't going through the burn pot and thus the fuel bed.

This will result in a lower flue temperature and thus allow combustion byproducts to condense out on various surfaces in the stove, including the flue pipe, even directly behind and above the burn pot.

While this isn't generally what is meant when someone says the fire is getting too much air it does (sort of) qualify.

 

[SmokeyTheBear]

stillersnut,

It could be "bad pellets" if the pellets are out of spec for the stove but say they are in spec and the stove is setup and operating correctly.

I would want to remove the stove and its operation from consideration before complaining about the pellets.

 

[jtakeman]

not wanting to cause a pi$$ing match here.................

TOO LATE! :lol:

Subscribed for the entertainment! hehe :lol: :lol: :lol:

But my vote is for incomplete combustion.

 

[Delta-T]

I know this is an "outside" thought, but any chance you're getting water coming down the pipe and collecting in the combustion chamber? I think the Thelins have the exhaust flange on the top, leading right into the combustion chamber. Then you'd have the vapor mixing with the smoke, condensing in the pipe....ect.

 

[stillersnut]

The Thelins vent directly from the back. I have however had rain/moisture within the pipe, mostly after heavy rain. Jay Thelin called me and asked about my set up. I have 3 90degree bends before it extends straight above roof, total length about 12 feet. Jay said to add 5 feet for every bend. With this all said the installers(a reputable co.) should of used 4" pipe instead of 3". Jay was indeed upset that a company selling his stove could overlook this. I do not have the extra $900 bucks lying around to buy all new pipe, so I will change fan, scrub pipe and cross my fingers. Yes in a couple years will probably be installing another fan. You just never know, or who to trust with install.

 

[jtakeman]

With that vent setup, I would NOT run that stove on low very much. Run it on Auto/Off and use a tstat. Try to keep the stove in a higher setting. Should reduce the build up. But I still would keep an eye on it. Clean and check more often!

You might be able to get a 3 to 4 inch adapter and just replace the outside pipe to 4 inch. Depends on the setup you have. Try to get the 3rd 90º to 4 inch. An increase tee works too, Also helps in the cleaning.

I have 3 90º's in my vent(long story don't ask). I replaced the last 90º with an increaser tee. Because the pipe is so close to the house I could not use the adapter. When the funds allow I will also replace the inside to 4 inch as well. Personally I think the all 4 inch would flow better!

 

[jimmie ray]

Well let's see about that folks,

Is there anyway that too much air (in effect) can cause incomplete combustion?

Yes, if the air isn't going through the burn pot and thus the fuel bed.

This will result in a lower flue temperature and thus allow combustion byproducts to condense out on various surfaces in the stove, including the flue pipe, even directly behind and above the burn pot.

While this isn't generally what is meant when someone says the fire is getting too much air it does (sort of) qualify.

Also, if the excess air is travelling through the burn pot, it can raise the flame and cause impingement onto cooler surfaces. With oil or gas fired products, this creates incomplete combustion, sooting, and CO formation - so I'd assume similar problems with burning wood?

 

[SmokeyTheBear]

The long and short of it seems to point to two forms of excess (maybe) air leading to incomplete combustion which in turn leads to 'sote formation.

The only thing possibly amiss with jimmie ray's version is that usually too much air through the burn pot results in pop-corning of fuel (both burning and unburned) out of the burn pot on at least the puffer versions of pellet stoves. Such are the gotchas with small objects in an air stream.