Can The Cat Be Active But Not Glowing????

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fdegree

Feeling the Heat
Oct 20, 2009
403
Southern Delaware
I just started my first fire in my new BK King, and I have noticed something that I didn't expect...this is my very first fire in my very first wood stove, so maybe it is me.

Fire was burning for over 2 hours...t'stat set on 2.5...cat is engaged and glowing...catalyst thermometer showing 1700°F
After an additional 1/2 hour, reduced t'stat to 2.0...catalyst thermometer drops to 1500°F...cat is still glowing , but noticeably duller glow
After another 1/2 hour, reduced t'stat to 1.75...catalyst thermometer drops to 1300°F...cat is slightly glowing, almost impossible to tell if it is glowing.
After another 1/2 hour...no t'stat change, the catalyst thermometer dropped below 1200°F...glowing completely disappeared
Left t'stat on 1.75 for another 1.5 hours...catalyst thermometer dropped to 900°F...still no glow
Stove fan was turned OFF the entire time.

So, with catalyst temperatures below 1200°F the cat is not glowing. Which raises my question: Is it still active/working?
 
Yes it's fine, it only glows at temps over 1000 or so. Usually it will glow for the first few hours depending on the size of the load. As long as your temps are over 500 it should be doing it's thing.

I had a small fire with 3 short splits in my Keystone this morning and when I engaged there was no glow at all but there was also no smoke out the chimney.
 
With my smaller fires this time of year I don't see a glow much at all - perhaps a few minutes after first engaging it. No smoke out the chimney (just some good ol' heat waves) though so I know it is working well.

In the Fireview manual and/or the online FAQ there is a statement to the "My cat isn't glowing is it still active" that answers this in the affirmative as well. Cat only has to be over 500* to be active - glow is from the material being hot enough to emit visible light which apparently registers somewhere at or above 1300* for your thermometer.

BTW - thanks for posting the observations on temps and glow. I don't have a cat probe thermometer and often have wondered what the correlation of glow to temps might be.
 
Congrats on the first burn. I see about the same thing that you observed. I assume you see no smoke out the stack after the initial burn off/closing the bypass?
 
Thanks everyone...that's good news. For some reason, I was expecting to see it glowing anytime the temp was above 500°F.

As for seeing smoke:
when the cat is glowing...no smoke
when the cat is not glowing, but around 1000°F...there is a little smoke.

But, I know I don't have ideal wood...white oak that has only been seasoning for 9 months...with moisture content ranging between 20% and 30%. I'm assuming this may be contributing to some of the smoke I see.
 
What color is your smoke?
 
That white oak will be ideal in a year or two. If you can't find anything else, I would load up the stove and do a good long burn off in the beginning. I do this with my chuglies that I am burning this time of year and they then light the cat right off and it burns clean even at the lower burn..
 
Slow1 said:
What color is your smoke?

It's a little difficult for me say for sure. It seems to blend in some with the clouds...we are having a lot of rain at the moment. But, as best I can tell, it appears to be greyish
 
SolarAndWood said:
That white oak will be ideal in a year or two. If you can't find anything else, I would load up the stove and do a good long burn off in the beginning. I do this with my chuglies that I am burning this time of year and they then light the cat right off and it burns clean even at the lower burn..

Thanks for the advice.

When you say "burn off" do you mean leave the bypass open and the t'stat turned all the way up?
 
fdegree said:
Slow1 said:
What color is your smoke?

It's a little difficult for me say for sure. It seems to blend in some with the clouds...we are having a ,ot of rain at the moment. But, as best I can tell, it appears to be greyish

The reason I ask is that if it is more of the white/light grey in color it may actually mostly be steam. When cat is running a bit cooler your flue temps will also be cooler thus allowing the water leaving to condense into visible droplets as it exits the top of your chimney. I don't generally see this until it is pretty cold outside but it will be a function of both the outside temperature (and your chimney heat loss) as well how much water is headed up your flue (i.e. how dry your wood is etc).

The darker your smoke the more unburned particles etc there is in it - if you have black or dark brown smoke that lingers around and you can see it 'smoking up the neighborhood' then that is bad. If you have white/gray smoke that dissipates fairly quickly and basically is gone then most likely it is mostly steam/water and nothing to be concerned about.
 
Slow1 said:
If you have white/gray smoke that dissipates fairly quickly and basically is gone then most likely it is mostly steam/water and nothing to be concerned about.

That is basically what it looks like to me.

Thanks!!!
 
fdegree said:
When you say "burn off" do you mean leave the bypass open and the t'stat turned all the way up?

Yes. But, if all you have is steam as opposed to smoke, it sounds like you are all set. When I burn stuff in the 20s MC without a good burn off, I get smoke at low burn.
 
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