New Install of Blaze King King 40 KE Stove on Six Inch Flue and Chimney

I’m already using windowstats when running my coal stove at 150-170* in shoulder season to 70* outside temps at the time of year that outside temps jump like crazy. Doesn’t waste that much fuel, so I could easily do it with wood.

 

Exactly. Wood use during these times for me have been minimal. For you, really nothing will change. You're already doing it.

 

We did make a swing down device like yours many years ago. Unfortunately UL ruled against it because it could drop down and hit some on the arm or wrist.

BKVP

 

Next they'll require helmets when loading as well. Too much bureaucracy!

 

Exactly my sentiments. Bunch of pantywaists.

 

Just want to update everyone on my burn experience with this BK40 as winter is winding down (11° this morning ). We've had some cold days down to -10 at night and a few warm days up to 60° last week. I have been thoroughly thrilled by the performance of the BK40 this winter. Not only has it maintained the temperatures I want in the house (74°-77°) during the nastiest days, it could easily get 10 hours of amazing heat output while still reloading on excellent coal bed to maintain the constant heat output. On the warmer days (30+) I just load very small wood amounts and turn down the stat, maybe even crack open a window. For me the 6" chimney turned out to work flawlessly. I thankful I tried it before tearing it out and installing the 8" right away. I'm extremely happy with this stove and would highly recommend it to everyone with a house over 2,200 sq feet and daily temperatures consistently below 25° through the winter and hitting the low negative temps as well. This stove will laugh at those temps. Blaze King, job well done on an amazing product!

On a side note, my normal wood usage using my Central Boiler E-Classic 2400 outdoor wood boiler was usually 10-14 full cord. So far, this winter, I have used 2 full cord as of Feb 23,2024. At this rate, it'll surprise me if I use 3 cord by winters end. I'm very happy with this as it correlates to many less man hours on the saw!

I will update with final numbers once heating season wraps up.

 

Sounds great!

 

Wished I'd seen this before last October!! I have a 6" flue and bought a Buck Stove Model 81 because I'd been told a stove with a 8" flue wouldn't work! The 81 is a very well build and nice stove, but it's too small!!! It just won't heat the house very well when its very cold or windy outside! My chimney is about 33' tall, I live in a split level, so drafting shouldn't be a problem? Thanks for the information!!

 

The Buck 91 is not typically considered "too small" and is a very capable heater. Are you burning a lot of wood and if so, where is the heat going?
I know the guys at Buck if you need to speak with them. Just send me a PM and I can get you a name/contact.

BKVP

 

My house is around 2500 ft so the stove's being pushed as it is because it's only supposed to heat 2700ft. I guess the old stove put out a lot more heat and had a bigger firebox is why the 81 struggles? I actually called Buck to ask about the 91 and was told because I had a 6" flu that it wouldn't work. I appreciate any advice!

 

There is ZERO question that old wood stoves had much higher top end Btu production.

We as manufacturers have to design wood heaters to pass a standard and using a prescribed test method. Unfortunately, this places restrictions on design and also increases issues.

Cleaner burning units are most often more efficient. As you make stove burn cleaner, and you get higher efficiencies, you complicate draft.

Also, remember how the old stoves like our, Fisher, etc had face melting temps, well they also did not have glass doors. So ever since 1988 and 1990 EPA regulation started glass doors are very common place, likely 99.9% of all wood stoves today. In order to help the glass stay as clean as possible, we change the way the air is brought into the firebox. Air from above has a different impact on the way the fire burns as to compared to older designs.

You can maximize heat out put by using smaller piece size and therefore increasing the total surface area available to combustion. Of course this will drastically cut burn times. I'd like to say you can have the best of both, but that would not be true. We suggest the largest possible pieces to extend burn times (glass gets dirtier) and tons of small pieces for greater Btu production (glass stays cleaner).

You could put a thermocouple on the stack and watch for temperature decreases. When you fall off the peak temps, you can load more fuel. This means baby sitting the stove, which is a pain.

I can tell you first hand, installing an 8" stove on 6" stack will restrict draft under identical circumstances. If you can improve the draft, you will increase the burn rate of the stove. Increasing the burn rate will produce greater Btu's but curtail your burn times. If I were a combustion engineer I would provide you all the math.

Instead, I have 27 years experience dealing with tens of thousands of customers. Those that try the reduce stack (and many have tried) a small percentage are happy. But some folks don't know how much they are missing because they are "happy" with their stove and the way it performs. On the other hand, those that step up to the 8" system (as tested), see higher performance in two ways on catalytic models.

First they see higher Btu production on the top end. Second, they can keep the combustor active at even lower burn rates.

BKVP

 

In your experience, is the reverse true too? (people that put a 6" stove on a 8" stack)
I would think that someone with a quality chimney (insulated SS...either liner, or SS pipe) of appropriate height, that they would have a better shot at being happy with a 6" stove, than someone with an 8" stove on a 6" stack...?
Obviously matched sizes is the ideal.

 

Again, probably not ideal, but it "works". Often 6" stove owners use 6" dbl wall to the ceiling support box and use a 6" to 8" transition at that point. Industry is pushing to get DOE funding to study all these variables that can and do affect draft.

BKVP

 

If manufacturers would go to the oddball of stove breech sizes, 7 inch, then all those studies would be less necessary (less tax dollars wasted) and more stoves would better fit current popular stove pipe and Class A chimney pipe already existing in most homes, because NFPA 211 already compensates and allows for a 1” inch variance in pipe from the stove breech.


Problem solved … at least without more tax money spent/wasted and without more regulations … which have already constrained the industry.

Going to 7” stove breeches would also eliminate major expenses of having to rip out an otherwise perfectly good chimney only to have to meet a regulation and resize the chimney, all to accommodate a simple change out of a stove.

These regulations requiring the “perfect” and most “optimal” stove/chimney match are my pet peeve.

I’m a guy that’s usually for the underdog, and in this case the underdog are folks who are already likely having to be frugal with their money, and more often than not, folks who have a hard time paying for a $3k-$5k stove, let alone the extra $3k-$8k labor bill for a most often unnecessary chimney swap.

 

Above edited…

 

There are exceptions of course, but many of the "new stove" buyers are replacing older stoves. If that holds true, than likely many of those chimney systems are also older. We know they do not last forever and many have probably had a chimney fire or two.

With every installation, a thorough inspection is a must. Just lifting the pipe and shoving a new stove under the pipe is not always advisable.

As far as the costs, I'm in total agreement. I still drive my 2000 F350 and can't find the desire or funds to spend $100k on a new truck. But if my truck had inspection and some issues that were safety related were pointed out, I most certainly would have the addressed. And when it comes to fire in a home, I think great attention should be pauid to the chimney system.

Of course folks that do not have an older chimney and are buying a new system are an entirely different matter.

BKVP

 

I was also referring to those people who in the last 5-10 years have already replaced their old stove with a modern EPA stove as well as paid a large sum of money to update their chimney. Some if these folks frequent these forums quite regularly and for whatever reason are replacing their EPA stove and updated chimney with another new stove that may require a different size chimney. They’re then stuck with tearing out a perfectly good chimney only to have to upsize or downsize to a new one. I’ve seen this exact scenario take place on the other forum you and I frequent.

What’s more some if these examples could have been prevented by more educated dealers/salesman…all at the expense of the consumer. It’s a shame too. Granted, it may not seem like there are that many in the grand scheme of things, but even if just a few examples happen on forums, then how many examples are we not aware of? Likely more than we think.

These sort if things are what I think make stoves with bi-metal thermostats/regulators so appealing. It’s nice to be able to set the dial and have it hold a temperature for a long period of time, something no tube stove has been able to extend much beyond 12 hour burns…and that only under ideal conditions.

 

It'd be nice to put an 8" flue in but my chimney is in the middle of my home and I'm sure I'd be looking at several thousand dollars. I had a Buck Stove insert in my fireplace on another chimney that I used for years and it's still being used by my son so I know Buck makes good stoves, it just that the 81 doesn't heat as well. On the plus side it doesn't use as much wood as expected and that little stove really drafts very well! Again, any advice is welcome!

 

That sucks! Same situation I was in with my Hearthstone Heritage. Expensive mistake.

 

For some reason, sales always seem to want to sell you a stove right at the sq footage on the label. Rated for 2700 and your 2500. Realistically, if rated for 2700, I wouldn't put it in a house bigger than 2000-2200 sq ft. Why is a bigger stove always considered "bad"? Just build a smaller fire.