"Stalling the cat"

[ksks]

I bought and had installed a BK King Ultra in my shop this summer. I've been getting used to it this fall/winter.

I've read about stalling the cat if temps are turned down too fast.

First question:
Does that mean the cat temp has fallen below below the active zone on the thermometer?

Second question:
Assuming the above, if you have a stove that is in the active range, how does it cool to the inactive range if its already burning hot and there is a supply of smoke?

Thanks.

 

[moresnow]

Explain your start up procedure. Add in what your wood moisture content is.

If your Cat gauge is heading for the inactive zone you will eventually lose your active Cat. It will stall. Or you are getting to the tail end of your burn cycle.

Your second question indicates that you may be turning your thermostat down to far for your stove to maintain the fire!

 

[ksks]

Sorry for the confusion. I didn't explain it well.
I don't think I'm having the problem, just wondering what it is...

People have said a cat can stall if you choke down the air too much at once. You should make a couple step downs instead of putting it on low right away.

But, if you have a hot stove, and the thermometer is in the active range, how does turning it all the way to low cause the cat to stall.

Why can't you go from high to low?

 

[Woody Stover]

if you have a hot stove, and the thermometer is in the active range, how does turning it all the way to low cause the cat to stall.

I guess if you go too low, there's not enough oxygen to keep the cat burning..?

 

[Rearscreen]

I'll take a stab at this. When I engage the cat on my Progress then immediately turn it down sometimes it doesn't catch. My reasoning is that I'm not sending super hot gasses through the cat to get it going. Just a guess.

 

[Rickb]

As far as I can tell this will happen if your draft is very low or your wood is wet. Mine I turn all the way from full to as low as it goes as soon as my cat gauge shows its active. I have only had it stall once and that was when I was using bad wood.

 

[lsucet]

Doing it in steps is a good burning practice. It is not supposed to stall cause you go one time deal to low unless you go too low that it will stall it. But including doing it with few steps, if the final setting is lower of what your setup can handle, it still stalling on you.
Some setups can ride the hole as we call it, and not stall the cat. Learn what you can do with your system/setup and you will get a consistent/predictable burns.

 

[jetsam]

I bought and had installed a BK King Ultra in my shop this summer. I've been getting used to it this fall/winter.

I've read about stalling the cat if temps are turned down too fast.

First question:
Does that mean the cat temp has fallen below below the active zone on the thermometer?

Yep! Cat is no longer reburning whatever combustables are going through it.

Second question:
Assuming the above, if you have a stove that is in the active range, how does it cool to the inactive range if its already burning hot and there is a supply of smoke?
Thanks.

The cat gets cooler than ~500°. Could be that you have weak draft and the stove turned down too far. With normal draft and dry wood you should be able to turn it down all the way. With wet wood you may not be able to turn it down below 50%, which would be a fairly hot fire with dry wood.

The stall point varies with draft and fuel quality. You'll get yours figured out with experience.

 

[ksks]

Thanks guys.

 

[Highbeam]

Has nothing to do with how fast you turn it down on a bk. Has everything do with how far you turn it down as every installation has a minimum thermostat setting that will maintain an active cat.

 

[ksks]

Thanks highbeam. That makes sense.