2019-20 Blaze King Performance Thread Part 1 (Everything BK)
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Our new BK Princess insert seems to run the thermometer completely beyond the Active range. And then it seems impossible to bring it back, whether turning the thermostat to low or leaving it at medium.
Yesterday morning, quite a bit of smoke was seen at the chimney top, while the stove was in this state.
In the evening after reload, the stove top was as high as 700, but after calming down, the fire held thru the night.
Through all of this, we are diligently following the directions in the manual. Temps have dropped to mid 30s outside, while the house was mid 60s in the AM.
Does all of this seem normal enough? I've been heating with wood for many years, and these prescription fires are not the same as the constant tinkering that I'm used to doing.
I kind of get the idea that all the wood in the box should be hot and ready to burn when the thermostat gets turned down. But the immense flaming makes things very, very hot.
Is the stove designed only for very cold outside temps and always gonna be a pain to use in the shoulder season?
Thanks in advance for any advice.
Yesterday morning, quite a bit of smoke was seen at the chimney top, while the stove was in this state.
In the evening after reload, the stove top was as high as 700, but after calming down, the fire held thru the night.
Through all of this, we are diligently following the directions in the manual. Temps have dropped to mid 30s outside, while the house was mid 60s in the AM.
Does all of this seem normal enough? I've been heating with wood for many years, and these prescription fires are not the same as the constant tinkering that I'm used to doing.
I kind of get the idea that all the wood in the box should be hot and ready to burn when the thermostat gets turned down. But the immense flaming makes things very, very hot.
Is the stove designed only for very cold outside temps and always gonna be a pain to use in the shoulder season?
Thanks in advance for any advice.
Nothing.
I must be rusty, but I threw my bypass and let it cruise for about 10 mins with the door cracked open
If your wood is dry, just get enough of it burning to get the stove temp high enough so that the cat will light off soon after you close the bypass, as evidenced by the cat probe temp rising fairly quickly up further into the active zone.
How long has your wood been split and stacked in the wind? How many rows stacked next to each other? Top-covered?
That's kind of what my intuition told me, but the Mrs. was sure we had to leave it "engulfed in flames for 20 minutes" as the manual states. Maybe those extra minutes are to drive off any excess moisture in the wood?
We just got this house in April, and we're going through some wood that was in a covered shed for an unknown time. Moisture meter has it at single digits or a bit higher, no more than 15%.
I'm also wondering if these mild weather fires can't combine the "kindling phase" and the "cordwood phase" of burning, as I would build what I think of as a regular fire meant to last about 12 hours. We're going thru an awful lot of our kindling trying to get a "uniform bed of hot coals" out of it. If the wood is dry enough, can I just build a campfire and shut the bypass when it's hot enough?
Ashful
Minister of Fire
This doesn’t sound like normal behavior at all, for a Princess. My first thoughts are air leak or extremely strong draft, although my Ashford 30 has no trouble remaining totally controllable on 30 feet of pipe, which really has me wondering if you have something preventing your stove from properly sealing.
A brandy-new cat can be a little hyper active, and there’s always a chance of it wandering momentarily above active range, but that’s not my normal experience. Mine usually holds in the upper half of the active range when new, and then spends most of it’s life in the 20% - 50% into active region, after the initial few weeks. I can completely kill the fire to black box, at any time, during any phase of the burn, so your description of it it running very hot seems abnormal.
Also, when it gets cold, it will amplify the behavior you are presently observing. Draft increases with colder temperature. If it’s running too hot now, in what you call your shoulder season, this is a bad sign.
I think it’s time to start posting some photos.
Indeed, we did kill it to black box by turning the thermostat down. This is when smoke was billowing from the top of the chimney.
It's been so black in there that we can't see the glow from the combustor, even when it's super hot.
It's been so black in there that we can't see the glow from the combustor, even when it's super hot.
It is normal for the cat meter to run above the active range, especially on a new cat but even a well used one. The primary use of that meter is to tell you the stove is hot enough to close the bypass.
Don’t bother measuring stove top temperatures. The catalyst under the stove top is over 1000 degrees and creates a hot spot.
That 20-30 minutes in high thing, that’s just too much and a waste of fuel in my experience. I run it on highonly until the cat meter approaches the top of its range which is only about 10 minutes with my dry wood.
Assuming your door seal is good I suspect your only issue to be fuel. The new manuals do a good job of telling you how to measure moisture content. Are you freshly splitting a 70 degree split and shoving the prongs deeply into the freshly split face? Single digit mc is rare. Also, how large are the splits? Wet wood and small wood can cause smoke. What color is the smoke? And does it smoke the whole time or just during the warm up?
My princess smokes a lot more than my other non cat stoves. Especially before settling in for the long cruise. It’s white smoke at first and then blue smoke and then after about an hour there’s nearly no smoke for the remaining 23 hours of that load. Reducing the smoke during that first hour takes a lot of skill and technique not found in the owner’s manual.
Ashful
Minister of Fire
Ahh... okay. I misinterpreted what you were describing. So no air leak, control is fine.
Going from a raging fire to shut down quickly can cause all sorts of issues in the firebox, the most exciting of them being back-puffing, when flammable wood gas is coming off the wood more quickly than the allowable airflow is sweeping it into the cat and it ignites in the firebox. Also, it’s easily possible to get into a situation where the volatiles and particulates are coming off the wood more quickly than the combustor can reburn them, particularly immediately after a major adjustment, but this should be a very temporary situation.
I’m confused by your original statement, though:
Going from a raging fire to shut down quickly can cause all sorts of issues in the firebox, the most exciting of them being back-puffing, when flammable wood gas is coming off the wood more quickly than the allowable airflow is sweeping it into the cat and it ignites in the firebox. Also, it’s easily possible to get into a situation where the volatiles and particulates are coming off the wood more quickly than the combustor can reburn them, particularly immediately after a major adjustment, but this should be a very temporary situation.
I’m confused by your original statement, though:
So you’re seeing smoke out of the hi money while the combustor is pegged beyond active, but where is your air control set when this happens? Where was the air control set prior to this? It’s not clear if this is happening when air is wide open, just after turning down, or after an extended period at lower burn setting.
Nigel459
Feeling the Heat
In my experience, yes absolutely. I think you're right that the "bed of coals" and "20 mins on high" is to drive out moisture, so if your wood is already very dry, which it sounds like it might be, that could be a part of your issue. I still suggest top down ideally tho.
Where does your cat probe read when it's cold? Mine was slightly off and had to be adjusted, makes better sense now. There are instructions on here somewhere...
Does sound like there may be other things going on as well, but wanted to put those thoughts out there. You'll get er figured. Good luck
Ashful
Minister of Fire
Hey Nigel,
I’m not going to say top down is bad, I really haven’t experimented with them to make any such conclusion. But I’ve put more loads thru my BK’s than any three average wood burners, and I’ve never had to resort to building a top-down fire to get one going, I’ve just always used the traditional (“bottom-up”?) method outlined in the manual.
If top down has any advantage, it’s likely beyond the scope of this new user’s issue, or at least that’s what I suspect.
I’m not going to say top down is bad, I really haven’t experimented with them to make any such conclusion. But I’ve put more loads thru my BK’s than any three average wood burners, and I’ve never had to resort to building a top-down fire to get one going, I’ve just always used the traditional (“bottom-up”?) method outlined in the manual.
If top down has any advantage, it’s likely beyond the scope of this new user’s issue, or at least that’s what I suspect.
“In my experience, yes absolutely. I think you're right that the "bed of coals" and "20 mins on high" is to drive out moisture, so if your wood is already very dry, which it sounds like it might be, that could be a part of your issue.”
yes! Getting the whole load rip snorting burning, hot, and looking like the bowels of hell for an extended period of time is a great way to create smoke and high cat temps when you chop down the thermostat setting. Especially if the splits are really small and ultra dry.
yes! Getting the whole load rip snorting burning, hot, and looking like the bowels of hell for an extended period of time is a great way to create smoke and high cat temps when you chop down the thermostat setting. Especially if the splits are really small and ultra dry.
I just fired up our new Ashford insert for the first time a week ago and a second time this week. I have a question about using the cat. I activate the cat when its in the active zone but I am noticing if I turn the heat output down to like med/low in a few hours it drops out of the active zone. Is it ok to do this overnight?
BKVP
Minister of Fire
Nigel459
Feeling the Heat
Fair enough, and for the record I typically (for the few times per year my BK needs to be lit) stick a quarter super cedar smack in the middle of a full load. Ha.
If his wood is super super dry, getting the cat up to temp asap is a priority, in order to avoid the "bowels of hell" as described by Highbeam. Top down could help with that I was thinking.
no not cold enough for them yet, I am breaking the stove in during the shoulder months taking advantage of the cooler weather
You must not turn the dial down so low that the cat runs low on fuel and goes inactive. That is called “stalling” the cat and operating the stove with the cat in the inactive range means the cat is not cleaning/burning the smoke so it will coat your chimney and puke out of the cap.
Turn it up a little higher until you find “your” minimum setting for the conditions that keeps the cat active.
got it. what do you do about overnight then? I'm thinking the stove overnight cant make it a whole 7 hours without dipping out of the active zone. Although I haven't really had a chance to play with that yet I have only done 2 fires in it
BKVP
Minister of Fire
Alpine1
Feeling the Heat
Find the lowest setting for your combination of stove-chimney (cat still active, always!) this requires a bit of experimentation
Build a nice bed of coals
Fill it as much as possible, Tetris skills can help here
Shut the door, let it go on high for 15/20 minutes
Set the thermostat at lowest setting mentioned above
Leave the built in magic do its thing
Repeat next morning/evening as needed
Note: lowest setting may vary during winter: as the temp outside drops, you’ll be able to turn the t-stat a bit lower
Ashful
Minister of Fire
I’ve not run an Ashford 25, but I’ve put about 40 cord thru a pair of Ashford 30’s over the last 4 years, and I have no issues making it 7 hours on all but the absolute highest settings.
The range of settings on most BK models is about 3x wider than the actual useful range. Put otherwise, on my stoves the knob turns clockwise to raise and counter-clockwise to lower, and my range is roughly like this:
High setting: 6 o’clock (= 4 hours per load?)
12 hour setting: 3:30 o’clock
24 hour setting: 2:30 o’clock
Stall point: 2 o’clock
Lowest setting: 7 o’clock
So, you can see, the knob range covers about 330 degrees of rotation, but my useful range between highest setting and stall point is only 120 degrees. My 12-hour (overnight) point is about 75 degrees rotation back from high.
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But with a BK one only needs to start the fire once a year in fall, right? Then it's on to reloading every day and a half. If so, then many less starts.
BKVP
Minister of Fire
Plenty...don't turn down thermostat too rapidly. That can cause a rich air/fuel ratio. The manual provides this guidance.
I'm a big top-down fan. Cleanest start you can do, since the smoke from the wood that is catching fire is being consumed by the flames above. And I think you're right that having the flame in the top of the stove will get the cat/upper stove hotter, quicker and allow light-off sooner, while getting less wood gassing. All of this works only if you have dry wood.
Like these guys said, once you establish your minimum air setting, your cat will keep eating the smoke until the wood is down to coals and there is no more smoke. This could be longer than 7 hrs or shorter, depending how much wood you loaded.
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