Blaze King: happens when you open the door with cat engaged?

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Rangerbait

Feeling the Heat
Dec 17, 2016
456
Shepherdstown, WV
I know the manual warns against doing this, but I want to burn down my coals wth the door crack, but done want to warp anything from the high temps. Can I do it?
 
Not with the cat engaged... you’ll be pulling cold air straight through the cat causing thermal shock. Also, spilling CO into the room. If the load isn’t all into the coaling stage, smoke will fill the room. It’s more than just a suggestion from the manual, it could have very bad consequences.
 
Not with the cat engaged... you’ll be pulling cold air straight through the cat causing thermal shock. Also, spilling CO into the room. If the load isn’t all into the coaling stage, smoke will fill the room. It’s more than just a suggestion from the manual, it could have very bad consequences.

Now that's the kind of feedback I was looking for. What is "thermal shock"?

So, is the recommended technique to keep the door cracked with the bypass open? Glowing coal bed, and I have 30+ feet of flue; I haven't experienced smoke spillage in any conditions.
 
Now that's the kind of feedback I was looking for. What is "thermal shock"?

So, is the recommended technique to keep the door cracked with the bypass open? Glowing coal bed, and I have 30+ feet of flue; I haven't experienced smoke spillage in any conditions.
If there was wood in there you sure would see smoke!
The cat is somewhere in the 800-1500 degree range. (Obviously varies greatly) if the door is opened, 75 degree room air rushes in and straight through the cat. That’s the cause of most all cat failures.
What’s with so many coals? I’ve had this happen with my non cats, but not my BKs. What model do you have? I’d guess an Ashford/sirrico?
 
If there was wood in there you sure would see smoke!
The cat is somewhere in the 800-1500 degree range. (Obviously varies greatly) if the door is opened, 75 degree room air rushes in and straight through the cat. That’s the cause of most all cat failures.
What’s with so many coals? I’ve had this happen with my non cats, but not my BKs. What model do you have? I’d guess an Ashford/sirrico?

It's a King...I have been burning a lot of Mulberry lately.
 
It's a King...I have been burning a lot of Mulberry lately.
Hmm. With a deep belly like that I’m surprised. Are you running it full tilt? Or possibly the wood isn’t well seasoned?
 
It's a King...I have been burning a lot of Mulberry lately.
Don't mean to hijack the thread but where did you get your BK? I'm not that far from you and can't seem to find a dealer anywhere close
 
I don’t see how the coals would be an issue then, especially with a 6” deep belly. The coals produce a large amount of heat, if the air is on high and the bypass is closed it will produce good heat. Opening the door and the bypass will be dumping much of it into the atmosphere.
 
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I don’t see how the coals would be an issue then, especially with a 6” deep belly. The coals produce a large amount of heat, if the air is on high and the bypass is closed it will produce good heat. Opening the door and the bypass will be dumping much of it into the atmosphere.

It sounds like I've just been reloading too frequently then, and not giving the coals a chance to burn completely down...got it wide open right now with blue flames dancing on top of a glowing coal bed.
 
I agree with webby. If the loading door is open you are sucking perfectly good heat out of your stove room to heat the front lawn.

I have never burned mulberry.

One thing i have done is dumped a couple quarts of hardwood lump charcoal on maybe a cantalope's worth of cord wood coals. From that i have a pretty good idea where in the active zone my needle sits when it is being warmed but essentially idle. When the needle starts slipping from there i know my coals are going out.

You might could run at full throttle in bypass for 5 minutes or so, and then reload the whole firebox on hot coals with fresh wood.

If you got a LOT of coals piling up you could just reload 2-3 splits on all those coals. Then re-engage the cat and leave the throttle at full. The fresh splits will feed the cat and heat your house for a couple hours while the coals are burning down.

The best thing for combustor life is to open the loading door as seldom as possible, filling the firebox with fresh fuel every time, and closing the loading door again asap.

I think webby explained thermal shock well and wont beat that dead horse.
 
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I agree with webby. If the loading door is open you are sucking perfectly good heat out of your stove room to heat the front lawn.

I have never burned mulberry.

One thing i have done is dumped a couple quarts of hardwood lump charcoal on maybe a cantalope's worth of cord wood coals. From that i have a pretty good idea where in the active zone my needle sits when it is being warmed but essentially idle. When the needle starts slipping from there i know my coals are going out.

You might could run at full throttle in bypass for 5 minutes or so, and then reload the whole firebox on hot coals with fresh wood.

If you got a LOT of coals piling up you could just reload 2-3 splits on all those coals. Then re-engage the cat and leave the throttle at full. The fresh splits will feed the cat and heat your house for a couple hours while the coals are burning down.

The best thing for combustor life is to open the loading door as seldom as possible, filling the firebox with fresh fuel every time, and closing the loading door again asap.

I think webby explained thermal shock well and wont beat that dead horse.

Yep, thanks to you both...I believe I get it now!
 
Minimize door open time. Just spin the stat to max to burn down coals.

I recall the king has a 9” deep belly, my princess has just 6”.
 
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I have trouble with coaling up with certain woods. Have had it happen with walnut, honey locust, but have not had much experience with mulberry. One thing you can do if schedule allows, without opening the door is to open stat wide open for a while, it will help get the coals to burning. If that doesn't work, then what I have found to work is to let it build up to a point, open 'stat and bypass, throw in a couple sticks of wood, preferably something that will burn down good like ash or oak, let it burn down as best it can with the door and bypass closed but stat as open as you can stand, then reload. I keep intending to get a coal fork made just because of this, to help remove ash without taking too many coals out the door. On the bottom end of the to-do list at the moment, as I am burning ash and oak.

I have finally been getting 24 hr burns on a load during shoulder season in my princess by opening the stat a bit of an evening, as it will sometimes stall out before morning otherwise. I load in the morning, turn it up a bit before bedtime. When I really need the heat, I load 3/4 load morning and evening for consistent 12 hour burns.
 
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