What's the harm?

[Ashful]

A few commented on my woes with achieving a proper light-off with the downdraft cat stove.

https://www.hearth.com/talk/threads/achieving-lift-off-in-the-downdraft-cat.116507/

Here's a new question... on those occasions where the cat does not initially light off, but instead hovers right around 450 - 550F, what's the harm in just leaving it cruise there? I find that if I lower the air with the cat in this state, it will initially follow the stove, dropping down below 400F. But, if I just leave it that way, maybe it would eventually take off? I've tried this for maybe up to 20 or 30 minutes, without success, but never longer. Should I?

 

[HotCoals]

The cat will usually fire off after awhile,that is if some smoke is being made. At least it does in my BK.
I have not charred enough but had the cat light off then stall and then come back on it's own...all with the air all the way down.

 

[Ashful]

Maybe I'm staying up too late and getting frustrated for no good reason, then. I always want to see these damn things light off and head toward 700F, before I lower the air and go to bed.

 

[HotCoals]

Maybe you need to start getting it ready earlier! lol

 

[Ashful]

Tell me about it! My schedule the last two weeks has me running around and working from about 6am - 10:00pm... actually, 10:30pm tonight. So, that's about as early as I can get started on loading the two stoves.

Two stoves status: one cat at 1292, other at 465 and rising... slowly.

 

[Ashful]

Well, I'm all talk. On the stove that wasn't taking off, I watched that cat probe drop to 438, with this ominous glowing 3.0 cu.ft. firebox just begging to do a major back-puff, and a scary cool stove pipe. I went back to bypass for about three minutes, then re-engaged the cat, and she took right off to 1300F. This engage / bypass / engage again is the same behavior I described in the other thread.

 

[ddddddden]

Sounds like it could be a draft problem. When you open the bypass, you dump heat into the flue, increasng draft. Are you having problems only with the stove which has questionable draft/chimney?

. . .on those occasions where the cat does not initially light off, but instead hovers right around 450 - 550F, what's the harm in just leaving it cruise there?

The harm might be that unburned smoke passing through the cat will gunk it up. . .anyhow, that's what "they" say. Maybe try it for a season and let us know how the cat holds up. As I understand it, the EPA warranty would require Condar to replace the cat, even if operator error were the cause of failure.

 

[jharkin]

The only harm is that when Ive had it stall like that on me, if you go outside the stack is bellowing smoke like I'm burning tires in an OWB.

Once it lights off it will clean up and any gunk in the cat itself burns off, but meanwhile Ive stunk up the neighborhood and if I do that daily its probably building up some nasty buildup at the top of the stack.