I asked this question on this board and also sent it to my breckwell pellet stove rep. Also to the best of my recollection this soot build up on my clapboards just happened the last two seasons. The first two seasons that I had my stove it did not do this. I clean my stove weekly and have it professionally cleaned at the end of the season. I don't see any smoke coming out of the vent. I can smell it and I can feel it but I can't see it.
The Breckwell Pellet Stove reps reply:
Sent: Monday, November 03, 2008 10:48 AM
Subject: Breckwell inquiry: soot removal
Good Morning
I am responding to your inquiry regarding soot stain removal from your siding.
I refer to a professional site that recommends 1st cleaning attempt when dry. (You are beyond this point.) The website is:
http://www.parish-supply.com/dry_cleaning_sponge.htm
Thereafter use of a citrus degreaser. Test an inconspicuous spot first to be sure it does not discolor siding.
Now, more importantly...why did the unit produce black soot?
Generally, there are 3 reasons the exhaust will produce any smoke other than gray (moisture.)
1) Improper operation controlling air mix in firebox.
2) Improper or restrictive vent configuration.
3) Excessive flyash build up before thorough routine cleaning (once per ton recommended.)
Solutions:
1) Air issue: stir burnpot daily to avoid clinkers or ash buildup. Observe flame when adjusting air and heat levels. Example: for levels 1,2; push the air damper rod all the way in and pull out about ½ inch For level 3, push closed and pull out about 3/4 inch. For level 4, pull all the way, or almost all the way open. You do not want so much air the pellets jump out of the burnpot, but you want a lively stiff flame that consumes most of the lellets before the auger drops more into the burnpot.
2) Vent issues:Too many bends or too cold a vent pipe slows the exhaust movement, which slows the burning cycle, causing a sooty flame in the firebox. The vent should terminate at least 6 inches from the building and pointing away and slightly downward. If this faces the prevailing winds, you are guaranteed to experience smoke issues and all exhaust will be blown against the siding. The only way to guarantee to avoid discoloration of the siding, in any case, is to rise above the roof and terminate vertically as shown in the owner's manual.
3) Cleaning: The owner's manual specifies cleaning schedules, and this is critical to a clean burn.
As the sparks fly up with the heated exhaust thru the top of the stove, the exhaust is routed down behind the fireback. The sparks cool and become flyash. These accumalate as a grey ash behind that wall and must be vacuumed out once per ton burned. This is done by removing the burnpot and then removal of the 2"x4" plates in the firewall. At the same time the exhaust fan should be lossened and lifted out, brushed and vacuumed.
If this is done regularly, each ton burned, the flame will burn very clean and the smoke will almost never be black...usually there will be only grey smoke visible.
I hope this helps. I recommend that whenever possible the vent should terminate above the roof, especially where wind issues come into play.
RMI Technical Support
