Measuring Chimney Draft

[Marshy]

Hope I'm not sounding like a broken record, but to clarify for others, the BKing is a great stove, if it is on the right chimney and not tucked away in a basement!
The King throws so little heat up the chimney that large brick/clay flue chimneys are not a good fit for the BK.
I doubt if you wrap the chimney up from top to bottom it would make much difference.

After some experimentation on my 28`brick-clay liner oversize chimney, I settled on the hottest burning EPA non-cat stove I could find and it can keep my 2 story 2500 sq ft home toasty warm with just wood heat. No way i could do that with a Blaze king on my chimney, even using stove fans and chimney wraps.

My bet is on your chimney having a decent draft already, but the King's even temperament is not forceful enough to crank the BTU's you need and want.

Bring on the Draft test

Thanks for the reply, it's nearly word for word what the BK rep told me last weekend about the stoves flue temp, thermal mass of the chimney and how wrapping it with insulation wouldn't make much difference.

It sounds like you might of lived this headache before. I'm going to PM you, I want to know more about your stove without detailing this thread. Thanks.

 

[stihly dan]

Is the reading in your picture -0.5 or +0.05? Do you read the end of the red mark on the right side?

The reading is saying +.05 but that really means -.05 because I have the lead swaped. As you can see the gage can only show down to -.05, so if you swap the lead it will read in the opposite direction giving a much wider scale.

 

[stihly dan]

had me one of those long ago. first windy day, sucked the water right out of the tube!!!! chimney in center of house,,38 feet tall!! whitespidey has hell draft like I do,, and def need a dampener!!!

Thats why a baro is good. Although for a stove a dampener is fine.

 

[mijdirtyjeep]

I live on rt64! Chimney has a cap. One suggestion I got was to take it off and see if that helps..

This made a big difference in how my stove works. From the top of my liner to the bottom of the cap was less than 4".

I have 4 notches on the rod for air control on my insert. With the cap on I could never push the arm in past the second notch or my stove would die right out. Once the cap was removed I can now close it all the way down and she will hum right along all night long without chocking out.

My insert has secondaries tubes and no cat, so maybe different results for yours.

 

[Highbeam]

The BK only produces such low flue temps (250-350) on the very minimum output. If you crank it up to the highest setting then the flue temps will easily bump past 800. These are internal flue temps, not surface temps.

The surface temps of the BK king can easily be 800 as well just like modern non-cats. An 800 degree stove is an 800 degree stove whether it is modern EPA or old smoke dragon.

I think your draft will be fine on high burn and you might just want to run this BK on high all the time which is not a bad thing. The BKs really are magical on lower settings but they can also do hot better than most.

So get your driest wood. Get a bed of coals established. Fill the stove to the top with firewood, engage cat when it's ready, and leave the thermostat all the way on high for the entire burn.

 

[Marshy]

The BK only produces such low flue temps (250-350) on the very minimum output. If you crank it up to the highest setting then the flue temps will easily bump past 800. These are internal flue temps, not surface temps.

The surface temps of the BK king can easily be 800 as well just like modern non-cats. An 800 degree stove is an 800 degree stove whether it is modern EPA or old smoke dragon.

I think your draft will be fine on high burn and you might just want to run this BK on high all the time which is not a bad thing. The BKs really are magical on lower settings but they can also do hot better than most.

So get your driest wood. Get a bed of coals established. Fill the stove to the top with firewood, engage cat when it's ready, and leave the thermostat all the way on high for the entire burn.

I agree with all of this. In fact, that's exactly how I've been running the stove, on high all the time. The wood is plenty dry. I haven't checked it with moisture meter or done the 2x4 scrap test but the wood burns really well and is heating my house. It maintains a burn until it's reduced to coals, it doesn't smother out.

I checked the draft with it on high and with a med/small size bed of coals, the stove havent been loaded in about 6 hours and it was drafting 0.02" wc.
I put some wood in it and left the bypass open and on high for 15mins or so and measures the draft at 0.045"wc. The draft didn't change from the 0.045"wc with the bypass open or closed. The conclusion is the draft is fine.

I was pulled into supporting an emergent issues at work and have been on a 12 hr night shift since Wednesday last week (sucks!). I haven't had a chance to use the IR gun to check stove temps yet but I will. The BK rep told me it will not have 700*F surface temps like my old stove. He said 350-400*F surface temps are common. The stove doesn't radiate heat like my old stove and that I need to more the air around the stove to get the heat out. When I get the IR gun I'll post pics. I have some pics of my old stove with the IR gun to compare.

 

[Whitespider]

Makes me glad I have a low tech EPA stove. My stove pipe is loose but drafts fine. Sorry about your troubles. I knew those BKs couldn't all be magical

There ain't no magic... never has been.
I hate to sound like a broken record... but... you flat cannot burn less fuel, over a longer time period, and get the same per-hour rate of heat generated... it ain't possible.
Marshy, I'm seriously sorry you're having troubles, but you're attempting to use what amounts to a space (room) heater to heat more space than it can... the more space you heat, the higher per-hour rate of heat output needed, something that cannot be accomplished in an appliance designed to both burn less fuel, and burn it over a longer time period.
Been there... tried that... failed.
*

 

[Marine5068]

That is the max output but that's the LHV rating. The HHV rating is closer to real world performance and is actually 48 KBtu/hr on high (averaged over 12 hours). I can tell you after 7 hrs on high its not enough heat to maintain the house temp. It will have a very healthy bead of coals but IDK what it would be like if I waited a full 12 hrs...

I called Blaze King yesterday and had a lengthy talk about the stove, my chimney setup, wood moisture and troubleshooting. I'm starting to think I might expect too much from this stove but I have to wait to confirm draft before I make that conclusion.

Wood moisture; BK rep said a new study performed suggests hard woods don't reach <20% moisture for 3 years and that 2 years is typically not enough time even if its stored under a roof. IDK all the details of the study but I think size of the split wood might have a lot to do with how fast the wood will season. He suggested I stoke the stove full of 2x4 scraps to see how it performs. If there is a significant improvement then the moisture in the my wood is too high and is causing the performance issue.

Thermostatic Draft Control; BK rep said they are set by the factory to protect the stove and more specifically the cat from being over fired. If the cat gets too hot then the material on the cat will melt and fuse into a smooth layer visible under an electron microscope. He said they have only ever had to replace a hand full in many years (doesn't mean it could be mis-calibrated from the factor IMO). He thought that was least likely the cause of poor performance.

Chimney Draft; After discussing my chimney configuration he felt the chimney was insufficient. Being a masonry chimney approx 25 foot tall with no insulated liner was a large concern to him. He said it didn't matter if it was on an exterior wall or through the center of the house in a chase way (like mine) or not, it's just too much thermal mass for the low flue temperature of the stove (approx. 350F). He said "we have never had a customer with a king model, hooked to an uninsulated/unlined masonry chimney that has been satisfied with the performance". He said even if it drafts properly he believes I will have a significant creosote issue in the top 3' of the chimney because the flue gas will get too cold and condense.

I wish the BK rep I spoke with before I purchased this stove shared the same level of concern. I discussed the chimney dimensions with the BK rep before purchase and he did not seem the least bit concerned. In fact, at the time he said I "have the best configuration one could ask for given a masonry chimney hookup". Disappointed does not describe how I felt after hearing this...

Regardless, I have to press on and figure out a solution. I have access to a FLIR camera (infrared imaging) that I can take pictures of the stove with. My plan is to install the DP gauge and measure the draft while I let the stove burn on high with my "seasoned" wood, take IR images and share them with BK. Then I will load it up with 2x4 scraps and take images with the IR camera and measure draft for comparison. If the draft is at the required 0.05"wc and the IR images of the 2x4 scraps closely match my seasoned wood then my conclusion is this stove does not meet my level of expectation for performance. If all of that checks out ok I sill might have a creosote issue to deal with but time will tell.

I also spoke with a few local chimney sweeps and no one had the tools to measure draft surprisingly. One guy said he's never had a customer that has been happy with the output of the new EPA stoves. He did say the stove fans are necessary through (I mentioned to him that I don't have them). He said they don't radiate the heat like the old stoves and that you really need to move the are a great deal to get the heating out of them.

Sounds like you may need a new insulated Superflu style chimney. Or sell the King and buy and new stove. Sorry for your troubles.

 

[olyman]

There ain't no magic... never has been.
I hate to sound like a broken record... but... you flat cannot burn less fuel, over a longer time period, and get the same per-hour rate of heat generated... it ain't possible.
Marshy, I'm seriously sorry you're having troubles, but you're attempting to use what amounts to a space (room) heater to heat more space than it can... the more space you heat, the higher per-hour rate of heat output needed, something that cannot be accomplished in an appliance designed to both burn less fuel, and burn it over a longer time period.
Been there... tried that... failed.
*

even with a few mods!!!!!

 

[Whitespider]

even with a few mods!!!!!

More than a few.
*

 

[Marshy]

Results are in. I climbed my chimney and had a look. Been practically burning it non stop on High the whole time. Here is what I saw.








As you can see, no creosote untill the top 12" of the pipe. Thats likely from the mixing of cooler outside air. Nothing but a light layer of ash throughout. I brushed the top 16" with hand and brush and called it good. The cap on the other hand was starting to clog up some. Nothing too bad but from now on I'm going to use that as an indicator that I need to go up and clean.

As far as the stove goes, I haven't bought the fans yet. Been making g due with a small 12" high velocity fan over the top. It still doesn't keep the house as warm as the old stove but it's doing the job. The lack of creosote in the chimney is reassuring to me. That was definetly going to be the deal breaker if it was making a lot. I'll update more in the future.

 

[olyman]

Results are in. I climbed my chimney and had a look. Been practically burning it non stop on High the whole time. Here is what I saw.

View attachment 546101
View attachment 546102
View attachment 546103
View attachment 546104
View attachment 546105
View attachment 546106

As you can see, no creosote untill the top 12" of the pipe. Thats likely from the mixing of cooler outside air. Nothing but a light layer of ash throughout. I brushed the top 16" with hand and brush and called it good. The cap on the other hand was starting to clog up some. Nothing too bad but from now on I'm going to use that as an indicator that I need to go up and clean.

As far as the stove goes, I haven't bought the fans yet. Been making g due with a small 12" high velocity fan over the top. It still doesn't keep the house as warm as the old stove but it's doing the job. The lack of creosote in the chimney is reassuring to me. That was definetly going to be the deal breaker if it was making a lot. I'll update more in the future.

suggestion looking down the chimbley.......looks like some hack layed in the tile liner.. why??? because there is grout sticking out as far down as your pics show......if you could, take a piece of 1/4 metal,, that would fit down the chimney,, the same shape,, and gently knock that excess loose.. just a wonderful place for creosote to attach to........they should have smoothed it all off......

 

[GASPUMPCITY]

If you talked to bkvp then why are you not going with an 8inch Stainless steel liner? Same thing I did was told i have a slammer install

 

[Marshy]

If you talked to bkvp then why are you not going with an 8inch Stainless steel liner? Same thing I did was told i have a slammer install

The answer to your question is somewhere within the first two or three pages of the thread.

 

[laynes69]

If you talked to bkvp then why are you not going with an 8inch Stainless steel liner? Same thing I did was told i have a slammer install

If the stove is attached to a thimble on the chimney, it's not a slammer installation. The chimney has a liner. Placing a short section of pipe up a large flue of a fireplace would be a slammer.

 

[Marshy]

I've never heard of a slammer, maybe slang for something besides jail?
Anyways, you can't fit a 8" insulated pipe down a 7x7 hole. And yes, I have the stove hooked to the chimney through a thimble.

 

[Del_]

Results are in. I climbed my chimney and had a look. Been practically burning it non stop on High the whole time. Here is what I saw.

Looks really good!

Chimney caps do cut back on draft quite a bit. In my opinion mostly what a cap needs to do is to keep rain water out. The screening on the sides is mostly just causing draft reduction.

 

[Marshy]

Looks really good!

Chimney caps do cut back on draft quite a bit. In my opinion mostly what a cap needs to do is to keep rain water out. The screening on the sides is mostly just causing draft reduction.

It's a lot better than I expected. It might be largely due to well seasoned wood. Either way, I'm happy as a pig in ****. I was fearing a lot of creosote. We've had a few cold snaps but still fairly a mild winter so far.

I was considering leaving the cap off for the rest of the winter. Taking the wire off it might be something I try first. I had a chimney fire from a bird's nest one so come summer I could put something around it to prevent birds from getting in.

 

[GASPUMPCITY]

You are saying you have a clay liner from the thimble to the roof? Most masonry from the smoke chamber open up then go to clay liner yours?

 

[Del_]

I run mine without a cap. My chimney is 125+ years old and made of stones. I installed six inch inside diameter Selkirk Metalbestos chimney inside with a tee about six feet off of the floor of the fireplace and came out through the stone wall of the chimney. Has worked great for the past 16 years. I packed old fiberglass insulation in around the Metalbestos to fill the gag and cut air loss. I am sure you'd be fine with no cap during the heating season and you'll be surprised how much cleaner your chimney and roof area becomes. A cap is a huge collection point.