Bad Leyden combustor or too low temps?

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vaeevictiss

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Dec 29, 2012
13
So this is the start of the 3rd season with a Lopi Leyden. I seem to learn more and more about it every season and after reading up on exactly how these new EPA stoves work, i think i finally got it (yea was a slow learner on this one thing haha).

Anyway, while learning the stove the first two years, me and my wife tried all different things...now im curious if we messed up the combustor in that time.

First off, Ive read that the stove needs to get to 500 degrees for the combustor to ignite. Does that mean it also needs to stay at 500? Where is that 500 measured? Just with a mag therm on the top im normally running about 350 and it can quickly get the house to 80. There is no way i could constantly run it at 500 (again, this is based on the temp on the top.

Anyways, ive also read that once the combustor is working, you should see it glowing through the two slots in the bottom of the back plate. I have not seen that yet this season. I also read there should be no smoke out the chimney, and this seems to be hit or miss. Yesterday i had no smoke, today during the day i had no smoke, tonight, while the stove is burning no different, there is smoke.

Now, i will say that the house has stayed a comfortable 75-77 with a window cracked. Last night it stayed 76 through the night (all windows closed), and the load actually burned slower than it ever has which was great. Last season i couldn't seem to get a load to last the night.

Now you are probably wondering why im here if the damn thing is finally working like it should after 2 years lol. I just want to make sure that even tho it is providing the heat we need, is it still working like it should? I was concerned when i read about these three telltale signs of the combustor working, none of which ive had (well one intermittently).

1. No smoke out of the chimney (the intermittent one).
2. Glowing combustor
3. "deep howl" when closing the bypass.


thanks for any info on this.
 
also, just checked something...on the question of where to put the therm on the stove. On the top lid itself im at 550 degrees, but on the lip in front of the lid im at 350.
 
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When I get a load to last much longer than expected my first thought is to be happy I kept the house warm by using less wood. But my second thought is that I was running a bit of a creosote factory, because an abnormally long burn for a load of wood usually means the load didn't burn as hot and clean as normal. Less heat was lost up the flue, but less smoke was burned, meaning more went up the stack (and more creosote deposited, as well).

Rather than closely monitor stove top temps on my downdraft stove, which I find are not a reliable way to determine if/when the bypass damper should be closed, I monitor flue temps as well as keeping a thermometer on the back side of the stove (where the combustion chamber is).

If the secondary combustion is firing well, not only will there be no smoke but I will see a fairly rapid rise in the back-wall temp from 2-300 up to 5-600, even as flue temps show a slight drop. (Rather than a "deep growl", I more commonly get what I would call a "gentle woosh" -- but if I get NO sound at all, I know that the burn chamber is NOT firing.) The secondary combustion may not succeed because of...

- insufficient fire size and/or coal bed depth to maintain adequately high temps
- shutting down primary air too far and/or too fast
- clogged or damaged combustor
- wood is green/wet
- poor draft
- etc.
 
Everything sounds normal to me. You do not need to see glowing in order for the secondary combustion to be working. The occasional smoke is also normal, like any stove. Sometimes there is more smoke being produced than the combustion system can consume. As long as it's no belching smoke, blowing the top loading door open, or the entire back of the stove isn't glowing I'd say all is good! ;lol
 
Hmm well now I kind of want to check that combustor out but with all the cold weather coming I'm not sure when id feel comfortable with all the down time. Maybe we'll get a lucky warm weekend soon.

How slow should I be taking to shut the primary air down? Also, do I need to taper down the bypass also or can I close that in one shot?

So IF it is a bad combustor, how much do those run?
 
The bypass is either open or closed, no in between. I didn't really wait any certain amount of time before I reduced the air on mine. After it was up to temp, usually reduced it to half or so.
The combusted is probably still under warranty. It's not hard to get to, it just takes a 3/8" socket if I remember right.
 
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