STICKY BLACK MESS

[Gilly]

JUST COMPLETED MY FIRST DETAILED YEARLY CLEANING ON MY HARMAN ACCENTRA INSERT. I HAVE A LOT OF BLACK STICKY FILM ON THE HEAT EXCHANGE BAFFLES. HAVE BEEN SCRAPING IT OFF WITH A RAZOR BLADE (TEDIOUS AND TIRING!!)

I'M CONFUSED - I DIDN'T HAVE ANY OF THIS BUILD UP THE FIRST FOUR MONTHS OF BURNING MY STOVE. ONLY STARTED OCCURRING WHEN I WAS BURNING "HOMEWOOD" PELLETS. IS IT A PELLET PROBLEM, OR POSSIBLY AN AIR SUPPLY PROBLEM?

DOES ANYONE KNOW OF A PRODUCT THAT CAN BE APPLIED TO GET THE STICKY BLACK FILM OFF MORE EASILY?

THANKS FOR YOUR TIME!

 

[jtp10181]

Can you turn off Caps Lock?

 

[KeithO]

The moisture content of the last batch of pellets was too high ? Did you notice a reduction in heat output (had to run at a higher feed rate for the same heat) ?

 

[pelletheat]

If you just completed your "year end stove cleaning" in August, the ash build up may have drawn moisture from the outside humid air into the stove when it was not in use. I would clean the stove throughly before pinning the problem on the pellets and watch closely when you start burning in the fall.
Make sure to clean the exhaust tube (very important for combustion air flow) with the brush, if the exhaust tube is "plugged" with ash it could have possibly caused your problem. Check the the right rear corner near the combustion blower fan for blockage. Slide the insert out and remove the cover with the wing nut for feeder body, inspect and clean any pellet fines from the feeder body. Harman reccomends doing a through cleaning after burning 1 ton of premium pellets and more often if burning "econo" high ash pellets. Here is a link from the Harman website on maintainance for the Accentra insert.

(broken link removed to http://www.harmanstoves.com/maintenance/accentrainsertcleaninginstructions.pdf)

 

[Gilly]

Can you turn off Caps Lock?

Thanks for your all of your help and advice...

 

[Gilly]

The moisture content of the last batch of pellets was too high ? Did you notice a reduction in heat output (had to run at a higher feed rate for the same heat) ?

Maybe the moisture content was too high. I didn't notice a heat output reduction.

Thanks

 

[Gilly]

If you just completed your "year end stove cleaning" in August, the ash build up may have drawn moisture from the outside humid air into the stove when it was not in use. I would clean the stove throughly before pinning the problem on the pellets and watch closely when you start burning in the fall.
Make sure to clean the exhaust tube (very important for combustion air flow) with the brush, if the exhaust tube is "plugged" with ash it could have possibly caused your problem. Check the the right rear corner near the combustion blower fan for blockage. Slide the insert out and remove the cover with the wing nut for feeder body, inspect and clean any pellet fines from the feeder body. Harman reccomends doing a through cleaning after burning 1 ton of premium pellets and more often if burning "econo" high ash pellets. Here is a link from the Harman website on maintainance for the Accentra insert.

(broken link removed to http://www.harmanstoves.com/maintenance/accentrainsertcleaninginstructions.pdf)

I clean the stove weekly (center and side plates out, scrape/brush air exchange baffles, punch wire brush down exhaust tube numerous times and shopvac everything). I cleaned out the fines in feeder (wing nut cover) every two months. The 'year end cleaning' was per the Harman guide, pulling out combustion/exhaust blower and detail cleaning. I cleaned my pipe with a 4 inch brush and flexible rod very thoroughly. I even pulled out the distribution blower and cleaned all the crap out of the vanes in the fan. (that was a pain).

Just confused about why the black stuff at the end of the season - just had the typical gray, powdery ash all winter and then suddenly - had the black stuff forming in there. Maybe it was moisture.

Thanks for your time and advice!

 

[buildingmaint]

This happened to me last Feb or March. Thanks to almost real time communications on this board I got some good advice on what happened and how to fix if my memory is correct. What caused my stove to do this was that the burn pot was not seated correctly. I got plenty of heat, but had a bad smell coming from the stove which is why I found the problem . Mine was so bad I could not scrape the heat exchange tubes. I cleaned the stove 's insides the best I could by scraping . blowing and vacuuming . Then just ran the stove as usual and it all burnt off. Good luck cleaning that stuff off I was a mess after I finished cleaning mine .

 

[pelletheat]

Your problem sounds similiar to what I experienced the previous heating season. After cleaning the exhaust tube twice during the heating season, I noticed near the end of the year I had a heavy black sooty build up on the left side of the heat exchanger and the glass was getting black. After cleaning & inspecting the stove I found a complete blockage in the exhaust tube in right rear corner, this caused a poor air to fuel ratio when exhaust gases were not able to exit the stove. Once I removed the blockage there was a huge improvement.
Near the combustion blower you can access the right corner of the exhaust tube by removing the cover with white insulating material (2 wing nuts?).

 

[HarryBack]

yup...sticky black mess....its not from a high moisture content in the pellets OR in the humid New England air. It is partly the stove and your failure to clean it properly. Have you cleaned BOTH tubes going to the combustion fan? The one on the left particularly is long and most folks fail to clean it well.....push your brush in further, because there is a bend in that tube that makes a guy think hes "bottomed out"...not the case.....that tube will almost take the whole brush length! Then, unmount the stove, remove the combustion fan cover, and make sure you clean out the fan fins and the chamber around the combustion fan.

The sticky black stuff is the product of incomplete combustion, due to the stove not being cleaned enough or properly, or both. Fortunately, its also water soluble. Hope this helps.

 

[Jags]

....push your brush in further, because there is a bend in that tube that makes a guy think hes “bottomed out”...not the case.....that tube will almost take the whole brush length!

I don't know why, but talk like this makes me frisky!

 

[Gilly]

yup...sticky black mess....its not from a high moisture content in the pellets OR in the humid New England air. It is partly the stove and your failure to clean it properly. Have you cleaned BOTH tubes going to the combustion fan? The one on the left particularly is long and most folks fail to clean it well.....push your brush in further, because there is a bend in that tube that makes a guy think hes "bottomed out"...not the case.....that tube will almost take the whole brush length! Then, unmount the stove, remove the combustion fan cover, and make sure you clean out the fan fins and the chamber around the combustion fan.

The sticky black stuff is the product of incomplete combustion, due to the stove not being cleaned enough or properly, or both. Fortunately, its also water soluble. Hope this helps.

Harryback - despite my weekly cleaning during the burning season (and I am pretty thorough about it) I am still a novice and have much to learn! You have hit the nail on the head with the left combustion tube - I haven't been putting the rod in far enough. I usually just push it in until it meets the back bend and that's it. I did remove the combustion motor and detail clean all the fins last week. Must be pretty dirty in back there as I burned 4 tons of pellets in my first season.

Any other way to access that rear part of the combustion air tube? One of the other posts above mentioned taking the cover with two wing nuts off - I did this and met a layer of white insulation. Should I cut through that insulation to get to the tube?

I really appreciate the advice, sir.

Thanks

 

[pelletheat]

Step #5 in the cleaning instructions has pictures of the access area I refered to in an earlier post. The white insulating material is precut on 3 sides.

(broken link removed to http://www.harmanstoves.com/maintenance/accentrainsertcleaninginstructions.pdf)

 

[HarryBack]

yes, as ole pellethead said, the back of the tube dumps into the chamber where the combustion fan is.....theres a plate there you can remove, then cut away the white insulation, and you can get to the back....no biggie on the tube...its very common that folks dont clean it enough

 

[Highbeam]

Bahaha... Jags... thanks for the laugh. Here I was picturing a carburetor passage and getting it cleaned of varnish completely on a different train of thought than you. Good going.

 

[rich81]

Can you turn off Caps Lock?

HA?

 

[Gilly]

Harryback and Pellethead - thanks for all of the help. I sank that cleaning rod all the way in and it came out pretty dirty. (getting JAGS hot again now I would assume....) I will take that cover off, cut the insulation and address the area directly next.

Appreciate your time, gentlemen.

Good day.

 

[Gilly]

Me again........a full year has gone by since the sticky black mess. No problems last heating season. After doing my yearly cleaning about a month ago, I'm starting to burn again the last couple of weeks. Getting massive sticky black coating again! It is not a blocked ventilation tube this time. I did remove the teflon strips that the Accentra Insert slides out on. (they were tearing up). Could this have caused a mis-alignment with the gasket to the exhaust port on the frame? Seems to be running great - lots of heat, no smells, etc. Just this darned black stuff again....

Any further suggestions?

Thanks.....

 

[Jags]

Gilly - If we just stop and think about this for a second, maybe we can come up with something. First is the problem: Sticky black goo.

Sticky black goo can be caused by several things:

Unseasoned wood.
Burning at too low of temp
Exhaust gas cooling
Air leaks in stove or pipe
Restricted exhaust
Reburner (tubes or cat) not functioning properly
Poor draft

There may be others that could be added in to the list, but I think it would just be a variation of something on the list. Now heres the real deal. Your sticky black goo is being caused by one or more things on that list. Review your setup and burning habits, and start checking off the list, its GOTTA be there somewhere. And prove it, test your wood with a moisture meter, make sure you have thermometers (checked for accuracy in the oven) located in the proper position. Use the match or incense smoke trick to check for leaks, etc.

If anybody can add to the list, please feel free. This was just off the top of my head stuff. Something HAS to show up, its just too blatant and obvious that a problem is there somewhere.

Edit: Ahh crap, I forgot that this was a pellet stove. The above list obviously needs to be revamped, but the process of checking your system from head to toe is still the way to go.

 

[Gilly]

Thanks Jags - I will try and start to check these things. One likely possibility is the pellets - I am burning a new brand purchased from Tractor Supply Co. (made for them - it has their name on the front) This is the only truly new variable in the mix. Everything else is now as it was a few months ago when I was burning round-the-clock with nary a problem.

 

[Jags]

Thanks Jags - I will try and start to check these things. One likely possibility is the pellets - I am burning a new brand purchased from Tractor Supply Co. (made for them - it has their name on the front) This is the only truly new variable in the mix. Everything else is now as it was a few months ago when I was burning round-the-clock with nary a problem.

Ding, Ding, Ding. I think you may have found the "X" factor.

 

[Gilly]

I've got a pretty big inside space - 3200 sq ft. with a loft (22 foot ceiling in 'great room'). I run the stove off of inside air and haven't ever had a problem (NO OAK).

Thanks for the suggestion though...