Dirty Burn Has Me Flummoxed

I have a 55-TRP22 and have been problems getting a clean burn. I am burning Somersets. I will totally clean my stove and it will burn clean for 8 to 10 hours. Then, the burn pot will start filling up and soon the window is covered by a layer of black soot. I have played around with the settings on the unit, trying additional air (raising LBA) as well as lowering the feed level. What I have found is if I drop the feed rate below 5, the flame goes out. So, I have tried running it on a setting of 5-5-1 with a heat setting of 1 and blower setting of 3. I have raised the LBA as high as 9 with no discernible difference.

I've called tech support twice. The first time, they had me make some tweaks to the feed settings. Said I might need a control board. The second time, they said that a dirty burn is an airflow problem and to check gaskets etc. or it might be a pellet problem. Since I've got the Somersets, I figured, there's no way its the pellets. I checked gaskets by doing the dollar bill test on the door. Used a lighter to see if there was any leaks that would pull the flame around the windows or the hopper lid. I checked to make sure the hopper latches were tight. Everything seemed to check out right. So, on a whim, I decided to try a different pellet. I had a couple of bags of McFeeters. So, I stopped the stove once the pellets were just about gone, cleaned it really well. And started running the McFeeters through it.

What a difference. First, I found that the McFeeters were a larger pellet. Seems like there of a larger diameter. But, they also seem to be longer pellets as well on average than the Somersets. And so, while I'm not sure if the size was the issue, it seems like they fed MUCH slower than the Somersets. And, so for two days, burning the McFeeters not only did the burn pot not fill up. But, the glass only got a slightly yellowish hue to it. But, very faint. And I could see through it the whole time. So, this morning, I loaded up with the Somersets. By the time I got home, the hopper was almost empty, burn pot is full, and the window is covered with soot.

Anyone have any thoughts?

(BTW, it doesn't seem to me that the McFeeters put out the BTU's that the Somersets do. But, they smell good. REALLY REALLY good.)

Smokey, it's a refurb stove that I bought from Andy that I installed in October. I've heard of the leaf blower trick, but wouldn't think I'd need to do that this quickly. I have not disassembled the stove for cleaning since it is a refurb (and from my conversations from Mike this basically means it is a new stove, since they tear them down and rebuild them from the ground up.)

Also, to give you some idea of how it was installed, I did install the OAK. And, the venting was done with a new duravent pipe kit. Corner install, so I've got a 45, 1.5 feet of horizontal run through the thimble to 3 feet of vertical to a 90 with the cap. Not sure what other information might be helpful or what else I should do to try to get this to burn cleaner.

SmokeyTheBear said:

How many bags have you put through the stove and what pellets were they?

Is that venting 3" or 4" and is your horizontal run going up grade from the stove and through the thimble?

Some (ain't that right Dexter?) will argue with me but based on several tables I've seen you are at or over the limit for 3" pipe and if your location has any altitude or there is any breeze entering the vent but not the OAK and that the pellets burned produce a lot of ash you might be suffering from good ole ash in the plumbing restricting your air flow.

I count your EVL as follows 45 horizontal 5 or 6, 1.5 feet horizontal 1.5 making it 6.5 or 7.5, 90 degree to go up 5 making it 11.5 or 12.5, 3 feet vertical 1.5 making it 12.5 or 13.5, 90 degree bend to go to cap 5 making it 17.5 or 18.5. now if I don't take into account the orientation of the 45 you end up with either 15 or 15.5.

Any down slope in the horizontal or lean away from vertical in that vertical makes it even worse as does any real altitude.

If you start out with quite a bit of resistance in the vent system it takes very little ash to make a mess of things and once that happens you get even more ash. It is a choking spiral of oxygen deprivation for the stove.

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Until I put the McFeeters through it, I had only burned Somersets. I have maybe put through 20 or 25 bags. Generally, they are not seen as an ashy pellet. So, I'm kind of finding it hard to believe that would be the case. Also, I've been very religious in my weekly cleanings. Shutting the stove down, vaccuuming it out, etc. Does the vent pipe need to be cleaned on a weekly/monthly basis as well?


My horizontal run is pretty much level. Not much rise, if at all. My OAK is right below the vent, so I would imagine any breezes that would impact the vent would be blowing through the OAK as well?

When I talked to the guys at Englander they seemed to think I was within the EVL limitations. I really tried to do everything "by the book". The only thing that I don't have is that rise in the horizontal run. The Duravent installation guide doesn't specify that which kind of ticks me off. I guess I'll unhook the outside pipe tomorrow, unhook the thimble on both sides and adjust to get some rise. Based on a foot and a half run, what do I need to raise it? I've seen 1/4 in. per foot. I've seen 1/2 in. per foot. Should I err on the side of caution and go higher?

Bought a leaf blower and tried the leaf blower trick today. Don't think I got the seal I needed with the duct tape, but did get some stuff blown out. Due to some scheduling conflicts, I didn't have time to adjust the rise of the horizontal run. So, I'll try to attack that as well as get my blower modified better to do the LBT. Gave the stove a thorough cleaning and we'll see if I see an improvements.

BTW, I did the math and so far I've put 32 bags through it. It's not been very cold, so it's been a lot of stops and starts. And, when it's run, its been run on a 1/3 setting. Even at that setting, we're cooking most of the time. But, I do believe that from what I've read, the lower burn rates can result in higher ash build up leading to a dirty burn as well. I'm going to try to get through this winter on the 3" pipe (adding the rise in the horizontal run as soon as I can) and probably will upgrade to 4" pipe for next season.