Blaze King install puzzle

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kennyp2339

Minister of Fire
Feb 16, 2014
6,693
07462
. I'm learning that slow-burning cat stoves are incredibly sensitive even more than I thought to draft, pipe insulation, wood quality,
We tried telling you in the beginning of your thread.
 
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Slate Dale

Member
Dec 27, 2021
161
Slatington, Pennsylvania
Those extra 3 ft are not a good idea; coldest place with worst pipe. (It's also against code.)

Is the pipe where you put your hand single wall? Being able to put your hand on single wall in your basement is not good. On double wall, I can, depending on how high the Tstat is (i.e. on flue temps). If I'm running low, the flue temps are near 300-350 F and I can put my hand on the double wall pipe I have. Running a bit higher, I can touch it, but don't want to leave it there..
I can easily remove that extension and bring the chimney cap back down near the chimney top level, just a few screws to remove. What is the code restriction for how much a pipe can extend above chimney top level? Is three feet too much? What is the limit in the code? Note that the place selling me the pipe recommended extending the pipes further above chimney level to improve draft performance. They said when they are extended above a certain height they require special bracing that they also sell, so I know it is being done in some places. My greenhouse stove pipe also extends quite a bit above the greenhouse, and would that violate code?

When I find the missing infrared thermometer, I'll post accurate temperature readings on the pipe sections indoors. The temperature definitely drops off from the vertical to the horizontal to the 45 angle going into the wall. I'm going to be offline most of the rest of the day, will check back tonight. Thanks to everyone for your help! This forum has been excellent help.
 

stoveliker

Minister of Fire
Nov 17, 2019
6,165
Long Island NY
I understood the three feet were single wall. If it's class A, it's ok
 

Slate Dale

Member
Dec 27, 2021
161
Slatington, Pennsylvania
Hm.
The 12 hrs is a concern we can discuss later.
Re: The water. No precipitation outside in the last 24 hrs?

Note that *any* burning will send many pounds of water thru the flue - the result of perfect combustion of any organic compound containing only carbon and hydrogen will be CO2 an water. See here:

Maybe your flue seam opens up when you heat it up.
Regardless, it's too cold if water drips - water should be vapor in your flue.
No precipitation in the last 24 hours and the chimney pipe has a cap.

Going to work. I'll check in again tonight.
 
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bholler

Chimney sweep
Staff member
Jan 14, 2014
30,101
central pa
I just checked the stove again for the dripping. Sure enough it is doing it now, even with pallet wood and 2X4 pieces, all completely dry from the barn, from a rack off the floor, been in the barn for years, never wet. I put in only three small thin pieces of my split cordwood this time, all with no bark and from the face of the stack near the stove, sure to be either fully dry or the driest that I have.

The stove had burned down to coals before I reloaded (so much for "+40 hours" on a full load, it's not even twelve hours, and the termperature control knob was set low, at the very beginning of the white band, as usual) and remember, the dripping only happens at the beginning after a re-load, then it stops, so there was no dripping since last night, and now it starts again after I re-loaded with wood that I know HAS to be dry.

Maybe no matter how dry the wood is, the stove still extracts moisture and it will collect and show itself at the bottom of that seam on the horizontal. Maybe the uninsulated two-foot passage through the wall is condensing the moisture and it runs down there. I understand that even a trace of moisture will rust this stove, so it must be stopped. I may stop burning the stove if it happens again with one more load of ALL 2X4 and pallet pieces.
Do you remember this statement?

Second was the performance part of the discussion. Smoke spillage as a result of insufficient vertical rise, thermostat responsiveness to radiant heat off surrounding solid (masonry) structure. We discussed drilling a hole higher up on the chimney and you reminded me of the short ceiling height. This stove is not going to work for your installation.
 

stoveliker

Minister of Fire
Nov 17, 2019
6,165
Long Island NY
Yes I do. The OP claims, however, to have the install now exceeding requirements (in vertical rise and clearance to the wall)?
 

stoveliker

Minister of Fire
Nov 17, 2019
6,165
Long Island NY
Maybe a pic of the install and measurements to go with it would be good.
 

kennyp2339

Minister of Fire
Feb 16, 2014
6,693
07462
Sounds like condensation is an issue, cooler then normal flue temps are warm the inside of the pipe and with the colder wx we are seeing the inside is condensing and dripping back to the stove.
 
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Slate Dale

Member
Dec 27, 2021
161
Slatington, Pennsylvania
Do you remember this statement?

Second was the performance part of the discussion. Smoke spillage as a result of insufficient vertical rise, thermostat responsiveness to radiant heat off surrounding solid (masonry) structure. We discussed drilling a hole higher up on the chimney and you reminded me of the short ceiling height. This stove is not going to work for your installation.
(1) I haven't had any problem with smoke spillage. Each time I open the door to reload there is no back-puffing, well only once that I remember when I swung the door open very fast and practically sucked some out. But no, there is no smoke spillage. Before I installed the stove I was doing negative pressure tests on the chimney pipe for a few days and there was usually a very faint downdraft, but that was easily reversed with a hairdryer for a few seconds and even stayed reversed for quite a while.

(2) I actually have more than the required minimum 2 feet of vertical rise, and with 30 inches I'm almost at the recommended minimum of 3 feet vertical rise from the stove top to the first angle. The tech I talked to at BK may have misunderstood, because I was concerned about the very tall "Ultra" stove base I received that would have reduced the vertical rise to less than two feet.

I would like to have the stove pipe go straight up through the roof of the house, but for me and many others, that isn't possible.

Note that the BK stove dealer and also his professional installer, who both actually saw the stove location, on two different occasions, both told me the stove would work fine here.

(3) There was always enough space from the stove to the ceiling. The stove as it stands now has much more than the 48.5 inch minimum distance requirement between ceiling and stovetop, and there is also about one foot more than than the required minimum distance between the pipe going into the wall and the ceiling. I think the main reason for not wanting to saw and hammer chisel through that mass of concrete again (18" thick foundation plus even more concrete that supports the upstairs hearth) to create a different hole was that it might weaken the wall and support for the hearth above it. I was following roughly the path of the hole made for the oil heater exhaust when the house was built. But it might still be necessary to carve out around the pipe I install to add some insulation and a second, outer pipe, and then make another form, and refill the carved-out space with cement. It will take a day, at least. I want to be absolutely sure that 30 inches of uninsulated pipe really is the problem before starting to tear up the wall again.

(4) I haven't been fully convinced that the stove doesn't work because I still don't have enough facts. I still don't understand the mechanics of the stove well enough. If it really doesn't work, I'll recognize that when I have enough facts. I'm not an easy quitter and I'm sure that most of you aren't quitters either. If many of you have great success with these slow-burning cat stoves, with so many precise, strict tolerances and requirements, I hope to learn enough to meet all those requirements and succeed as well.
 

stoveliker

Minister of Fire
Nov 17, 2019
6,165
Long Island NY
A stove running too cool might be due to the Tstat being too hot. What are your clearances to the back and side (and as I don't want to look up the manual, what is required)?
 

Slate Dale

Member
Dec 27, 2021
161
Slatington, Pennsylvania
Sounds like condensation is an issue, cooler then normal flue temps are warm the inside of the pipe and with the colder wx we are seeing the inside is condensing and dripping back to the stove.
I'm thnking the way you are. The stove is always set at the lowest temp, and I was afraid to set it higher because the cat thermometer on the stove top goes all the way up the white band and even a little over it. But the BK manual says to always set the temperature control knob all the way up for about 30 minutes after reloading to "condition the load." So when I reloaded tonight I tried that (I set the temperature control knob all the way up, to the end of the white band) and came back in about a half hour to findto my horror that the needle on the cat thermometer was at six o'clock, as far beyond the white band as it is possible to get. I immediately turned the control knob back, and I noticed it was a bit hard to turn. The needle started to drop slowly. I went back to check ten minutes later and it's still not quite back to the white area. That's the bad part. The good part is that no liquid came out of the seam on the angle fitting with this load, and the pipe going into the wall is really hot for the first time.

This morning I loaded with pallet wood and 2X4 pieces and had the temperature contol knob set low and there was just about as much dripping with that definitely dry wood as with my split cordwood that has unknown moisture. The cat thermometer went up almost to the end of the white band as usual.

The load that's in the stove now is all pallet wood and 2X4 pieces again, which I know is as dry, but not too dry. I read in the BK manual that using wood that is TOO dry can also damage the stove. I hope that following the manual's direction to run the stove on high for a while after re-loading did not damage the stove. I thought the thermostat was fail-safe and would automatically shut it down before reaching too high temperature.

The basement air temperature is about 70 degrees, but warmer near the stove. The concrete wall near the stove is very warm, and has been warm to the touch for days.
 

Slate Dale

Member
Dec 27, 2021
161
Slatington, Pennsylvania
A stove running too cool might be due to the Tstat being too hot. What are your clearances to the back and side (and as I don't want to look up the manual, what is required)?
There is much more than the required minimum clearance of 6." It is 10" away from the wall and there is plenty of open space all around the stove. The concrete wall is warm, and has been warm, near the stove as you would expect after days of burning. There is a fan running nearby force-drying a stack of split cordwood, so there really isn't any trapped still hot air lingering near the stove. The basement air temperature is about 70 degrees and higher near the stove.
 
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Slate Dale

Member
Dec 27, 2021
161
Slatington, Pennsylvania
The big problem or worry now is what might have happened from the cat temperature reaching six o'clock the highest point on the guage. Supposedly the thermostat is fail-safe and automatically shuts the air when it gets too hot. So much for the manual's direction to set it to High when re-loading. The cat goes crazy.
 

stoveliker

Minister of Fire
Nov 17, 2019
6,165
Long Island NY
as noted before, any new cat is hyperactive. This has happened to all of us. It has not resulted in problems as far as I know.

Now, the "conditioning" is to bake out remaining moisture. For dry (pallet) wood, there is much less of that. I do believe (based on my own playing around) that the wood nicely blackened is what makes a long and low burn stable.

As I noted before, *every* burn produces loads of water. See my back of the envelope calc in that post I linked to. Many assumptions (pure cellulose, perfect combustion, etc) but the point is many pounds of water are produced in your stove. If your pipe is too cool, it condenses.

Given that the clearance (Tstat overheating) seems ok, I think a major issue you have is that you did not run hot enough. Initially at least (the conditioning).

Finally, the Tstat *does* (if it works properly) limit the heat, but it does *not* shut the air completely. When setting it on high, it *will* result in a good amount of flames etc. It just won't make it more than it should be.
While I of course can't say that it worked or it did not work, I think your understanding ("So much for...") is not correct.
 

Slate Dale

Member
Dec 27, 2021
161
Slatington, Pennsylvania
as noted before, any new cat is hyperactive. This has happened to all of us. It has not resulted in problems as far as I know.

Now, the "conditioning" is to bake out remaining moisture. For dry (pallet) wood, there is much less of that. I do believe (based on my own playing around) that the wood nicely blackened is what makes a long and low burn stable.

As I noted before, *every* burn produces loads of water. See my back of the envelope calc in that post I linked to. Many assumptions (pure cellulose, perfect combustion, etc) but the point is many pounds of water are produced in your stove. If your pipe is too cool, it condenses.

Given that the clearance (Tstat overheating) seems ok, I think a major issue you have is that you did not run hot enough. Initially at least (the conditioning).

Finally, the Tstat *does* (if it works properly) limit the heat, but it does *not* shut the air completely. When setting it on high, it *will* result in a good amount of flames etc. It just won't make it more than it should be.
While I of course can't say that it worked or it did not work, I think your understanding ("So much for...") is not correct.
But did your BK cat temperature ever go to six o'clock? The needle can't go any higher on the guage, so who knows what temperature it really reached. It was a half hour from re-loading when the needle was in the middle of the white area, and I set the temp knob High, at the end of the white band, for the first time ever. I was always watching the needle on the cat temp guage, and going by that. I figured if the cat was reaching the end of the white area the it was getting too hot regardless of whether the pipe going into the wall wasn't too hot to touch.

I bought two CO alarms today, thinking that if the seams in adjustable angles can leak liquid, they can also leak gas. I had planned on using only fixed, solid angle fittings and I may change to that in the future when I'm sure this is how the pipes should be arranged.
 

stoveliker

Minister of Fire
Nov 17, 2019
6,165
Long Island NY
I have been well beyond the white area on the cat gauge. I have had no issues from that. (Tho this is my first cat, so I don't know its lifetime yet.)

You should always have CO alarms and smoke detectors on every floor.

Leaks in stove pipe suck in gas (when the flue is hot. The end of a burn cycle that is less so, hence detectors.
 

stoveliker

Minister of Fire
Nov 17, 2019
6,165
Long Island NY
Now I don't aim for going beyond the active range and wouldn't let it happily stay there for hours. But that it happened should not be a concern imo.
 

Highbeam

Minister of Fire
Dec 28, 2006
19,986
Mt. Rainier Foothills, WA
The thermostat does not monitor the cat temperature. It’s purpose is not to regulate cat temperature. The thermostat is driven by stove temperature which can be quite low even when the cat is quite hot.

I think you’re running this thing too cold and the condensation running down your flue is because your masonry chimney is cooling the flue gasses below the condensation point.
 

Slate Dale

Member
Dec 27, 2021
161
Slatington, Pennsylvania
The thermostat does not monitor the cat temperature. It’s purpose is not to regulate cat temperature. The thermostat is driven by stove temperature which can be quite low even when the cat is quite hot.

I think you’re running this thing too cold and the condensation running down your flue is because your masonry chimney is cooling the flue gasses below the condensation point.
It's not really a masonry chimney. It's rigid stainless lined chimney insulated with vermiculite cement. Two inches of vermicuite cement is supposed to be equal to the blanket insulation that is used around flexible liner. The vermiculite cement thickness varies from 1 to 3 inches around the pipe. The recipe was heavy on the vermiculite, minimal amount of Portland cement, and it was mixed by hand to keep it loose. I helped it to fill all the spaces by using vibration and a long rod.

The three foot extension above the chimney top is just the single wall with no insulation.

Instead of using pallet wood and 2X pieces, I re-loaded this morning with smaller, lighter-weight (no oak) and no-bark pieces from my regular supply of split cordwood that is finish-drying indoors with a fan. I had looked inside the stove and didn't see anything different about the metal parts (nothing seemed warped) around the cat after it reached a very high temperature last night (but I couldn't see if anything was warped in the back and around the bypass door) so I decided to try setting the knob at high again. In less than ten minutes the cat temperature was going beyond the white area and at about twenty minutes I moved the knob to medium.

This time there are a few drops of liquid at the seam, perhaps because I used cordwood again and/or because the flue pipe became less warm on low setting overnight. On the low setting yesterday even very dry pallet and 2X produced this much liquid, but not on high setting. The pipe going into the wall was not too hot to touch before I re-loaded, but the concrete wall around the pipe was still hot, which means that the thermal mass of the wall rising in temperature day by day and is beginning to help the pipe heat up quickly. The pipe going into the wall became very hot quickly this morning.
 
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stoveliker

Minister of Fire
Nov 17, 2019
6,165
Long Island NY
you have water because it's not hot enough.
Again, the cat probe going beyond the range is normal for a new cat. You need the high temp in the flue to avoid condensation of any water. If your pipe a few feet from the stove is already below water boiling temps, you are just not hot enough. This is why they recommend insulated pipe: keep it warm. Or you'll have trouble.
 

moresnow

Minister of Fire
Jan 13, 2015
2,073
Iowa
Wonder if some of this water is from cooking/baking your concrete/vermiculite mix?
 

Highbeam

Minister of Fire
Dec 28, 2006
19,986
Mt. Rainier Foothills, WA
Why do you care if the cat thermometer goes past the white? The cat thermometer has one important or relevant data point which is the active/inactive line. It can be considered an idiot light or on/off switch. Does your owner’s manual tell you to never let the cat meter rise above the white active area?

I admit that I don’t do the 30 minute full throttle bypass closed routine per the manual. I burn softwoods and after 15-20 minutes my flue temps are getting dangerously high so I reduce air at that point and prepare for the cruise. I use the flue thermometer after closing the bypass.
 

stoveliker

Minister of Fire
Nov 17, 2019
6,165
Long Island NY
Having done much oak and much pine lately, I can second @Highbeam : for softwoods (pine at 15-16%) I don't go 30 minutes. For (red, 18%) oak, I do. But I do keep an eye on my flue temp, and (given my tall chimney) "full throttle" means i go full, and slowly dial back keeping the flue below 900-950 F once it gets hotter.
 

Slate Dale

Member
Dec 27, 2021
161
Slatington, Pennsylvania
Wonder if some of this water is from cooking/baking your concrete/vermiculite mix?
The vermi-cement is outside the pipe and has no contact with the exhaust. It's just the moisture in the exhaust condensing. Maybe its not really an extreme amount of moisture but looks like a lot because most or all of it happens to be visible, instead of draining invisibly back to the stove. It happens to be collected where the chimney pipe meets the short section of horizontal stove pipe, and released (into a metal container I put below) drop by drop from the bottom of a seam in an adjustable fitting that created the horizontal.

If I have collected almost a quart in almost a week of burning, maybe that's not an unusual amount of liquid. But there shouldn't be any liquid. There shouldn't be any condensation at all.

Running on low, with the knob set at the very beginning of the white band, the dripping continues until the wood is charred, even with dry pallet and 2X wood. But running on High, there is little or no dripping as the wood is "conditioned," but the cat temperature gets extremely high.

I have a plan for eliminating the short horizontal and the 90 elbow and maintaining the 30 inch vertical rise, and still have the required 6 inch minimum distance of the thermostat box from the wall. It might be good that I tried it this way first, because it made the problem of condensation visible and otherwise it might have gone undetected.

SAM_1997.JPG SAM_1994.JPG SAM_1999.JPG SAM_1998.JPG
 
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