BK Ashford 30 Install

[Woody Stover]

Many of us have heated our houses just fine with bobcats for years.

I guess you're not a PETA member, then?

Any other cat stove will likely have the same draft issues....I'm certainly not the only person that has had creo problems with a BK. Many people I've talked to have stalled their BK at least once or twice a season and have gotten creo smell. If I had known there would be a risk of this I would have done things completely different. At a minimum I'd would have done the chimney completely different. Now I'm stuck trying to deal with what I have.
If there is a better drafting and better sealed cat stove I would certainly take a look but I have only seen worse stories with other stoves.

You seem to have a large circle of friends that burn wood. When you say that BK owners you talked to have "stalled" their stoves and had creo smell, does this happen when they run their stoves on a low cat burn with no flame in the box, or when they actually stall the cat and the probe falls out of the active zone?
What are the "worse stories" you have heard from people that have other brands of cat stoves? From what I've read here, the BKs are the only cat stoves that are very picky about draft...mostly the Ashford.
Yeah, you are going to lay out more money any way you go, new chimney or new stove. If you can use your Class A from outside, you only have to pay for the install, which shouldn't be too bad. Maybe less than the 2.5K+ you'd pay for a good quality stove, minus what you could get for the BK. I think a better chimney (inside the house with less turns) would probably get rid of the smoke to a large degree, and getting your draft measurements might support this theory. You may still have a little odor with the Ashford but people seem to put up with it.
BTW, no 45 elbows once you get above the ceiling support box into the Class A.

 

[brenndatomu]

I'm almost wondering if there is a little creo liquid dripping somewhere in the stove pipe and with a hot stove and not super high draft it is able to release some vapors into the house

Now that's an interesting idea...not likely, but certainly possible.

As for measuring the draft...there are a ton of those Dwyer Mark II model 25's in use around here...many on boilers and furnaces, but will work fine on a stove too. Hook the rubber tube up to the right port, left port left open...that will make it read the right side scale and give you more range. The meter needs to be perfectly plumb and level to read right.
As was mentioned, a piece of brake line or copper tubing works fine to insert into the pipe (or stove, in this case) only need a foot or two of it...clamp a compression fitting on the tubing (available wherever you buy the tubing usually) then the barbed fitting that comes with the Dwyer can be screwed into that fitting (1/8" NPT size, IIRC)...bam, draft reading.
And somebody mentioned that you can only take a draft reading when running wide open...not true...I run mine 24/7/365, it will give a reading anytime, even in the middle of the summer if you get some wind the right way. The one thing I would wonder about is if you would get a different reading in the stove pipe vs in the cat probe hole? (before vs after the cat)

 

[bholler]

Now that's an interesting idea...not likely, but certainly possible.

As for measuring the draft...there are a ton of those Dwyer Mark II model 25's in use around here...many on boilers and furnaces, but will work fine on a stove too. Hook the rubber tube up to the right port, left port left open...that will make it read the right side scale and give you more range. The meter needs to be perfectly plumb and level to read right.
As was mentioned, a piece of brake line or copper tubing works fine to insert into the pipe (or stove, in this case) only need a foot or two of it...clamp a compression fitting on the tubing (available wherever you buy the tubing usually) then the barbed fitting that comes with the Dwyer can be screwed into that fitting (1/8" NPT size, IIRC)...bam, draft reading.
And somebody mentioned that you can only take a draft reading when running wide open...not true...I run mine 24/7/365, it will give a reading anytime, even in the middle of the summer if you get some wind the right way. The one thing I would wonder about is if you would get a different reading in the stove pipe vs in the cat probe hole? (before vs after the cat)

No one said you can only take a measurement when running wide open. But that the conditions under which bk tells you what the draft should be. So yes of course you will get a reading anytime but you don't have a spec to meet any other time.

 

[brenndatomu]

No one said you can only take a measurement when running wide open. But that the conditions under which bk tells you what the draft should be. So yes of course you will get a reading anytime but you don't have a spec to meet any other time.

Yes, I think I misunderstood what I read.
So why wouldn't they give you a spec for anything other than wide open?
Wood furnaces typically require -0.04 to -0.06" WC...so unless you are just starting a fire, or the fire is dying out, the draft should be in that range...why would a stove be any different? Something to do with being a cat stove?

 

[lsucet]

Yes, I think I misunderstood what I read.
So why wouldn't they give you a spec for anything other than wide open?
Wood furnaces typically require -0.04 to -0.06" WC...so unless you are just starting a fire, or the fire is dying out, the draft should be in that range...why would a stove be any different? Something to do with being a cat stove?

I think some furnaces use some kind of draft control. They want the high burn to not exceed those numbers to prevent damage to the appliance and over fire? Another point to look is, when you shut the air the flue create higher vacuum making the reading higher.

 

[bholler]

Yes, I think I misunderstood what I read.
So why wouldn't they give you a spec for anything other than wide open?
Wood furnaces typically require -0.04 to -0.06" WC...so unless you are just starting a fire, or the fire is dying out, the draft should be in that range...why would a stove be any different? Something to do with being a cat stove?

Like isucet said above many furnaces use barometric dampers so you can set the draft over all conditions. With woodstoves you can't do that so they specify draft at a certain point.

 

[brenndatomu]

I think some furnaces use some kind of draft control.

Some do...some don't.
And yes, they want to never exceed the max draft, and they require the minimum draft spec to be met at all time while actively burning, except as I said, when fire is building, or dying out.

 

[brenndatomu]

Like isucet said above many furnaces use barometric dampers so you can set the draft over all conditions.

A baro only controls max draft...not the minimum...the chimney system does that, as you know.
EDIT: not controls min. draft...more like provides...as in a good chimney will, a poor one might not.
And yes, baros do a pretty good job of keeping the draft "in the range" over varying conditions like intake damper open, or closed.

 

[brenndatomu]

I guess my point is this, if you test the draft under wide open conditions only, many chimneys will pass since you are wasting a fair amount of heat...but once the stove is turned down and cruising, the heat wasted up the flue is much less, and a "poor" chimney system may lose sufficient draft to keep the stove working properly...which it sounds like there may be a pretty good chance of this happening to the OP here.
I would bet that 80-90% of "undesirable" chimneys pass the draft test under WOT conditions...not a good way to test IMO.

 

[bholler]

I guess my point is this, if you test the draft under wide open conditions only, many chimneys will pass since you are wasting a fair amount of heat...but once the stove is turned down and cruising, the heat wasted up the flue is much less, and a "poor" chimney system may lose sufficient draft to keep the stove working properly...which it sounds like there may be a pretty good chance of this happening to the OP here.
I would bet that 80-90% of "undesirable" chimneys pass the draft test under WOT conditions...not a good way to test IMO.

After testing many stoves on many chimneys what you are saying is very uncommon. 90% of the time if you test and meet draft specs under high fire the stove will work properly.

 

[bholler]

A baro only controls max draft...not the minimum...the chimney system does that, as you know.
EDIT: not controls min. draft...more like provides...as in a good chimney will, a poor one might not.
And yes, baros do a pretty good job of keeping the draft "in the range" over varying conditions like intake damper open, or closed.

Yes i know how a baro works. Of course you need to have the minimum draft but as long as you have that you can set the baro to control max draft.

 

[ValleyCottageSplitter]

It was 70 today but getting back in the 40's for the rest of the week. The Dwyer Mark 2 arrived today. The 3/16" pitot tube style pressure tip fits great in the cat probe hole and the magnet seats nicely on the stove top. It is very similar diameter to the probe. Hopefully nothing burns or melts right after the combustor...

 

[Highbeam]

It was 70 today but getting back in the 40's for the rest of the week. The Dwyer Mark 2 arrived today. The 3/16" pitot tube style pressure tip fits great in the cat probe hole and the magnet seats nicely on the stove top. It is very similar diameter to the probe. Hopefully nothing burns or melts right after the combustor...

It’s hotter than heck right after the cat. 1500 right now on my stove. Hopefully you don’t expect plastic or rubber tube to survive there.

 

[ValleyCottageSplitter]

Right. The BK gauge goes from 500-1500°F on active?

So this fits nicely in the cat probe hole. Will it be any cooler 2ft up at the elbow? Another option is to run a smaller load and pull it out once the cat is active. It would be nice to see what's happening when it normally produces creo but that is usually in the medium or high range. Second option is to leave the tip up a few inches to keep the barb cooler. Last, I could make a new 1/4" hole in the pipe but I'd have to go find a large sheet screw to fill it.

It's a silicone hose rated for about 500°F

 

[lsucet]

Load the stove normal. Not packed but full, after the cat is active and bypass closed run it on high as by the book 20 minutes or so. It depends to type of wood in use, just be sure that is running on high. Measure draft to see what it has.

 

[brenndatomu]

Right. The BK gauge goes from 500-1500°F on active?

So this fits nicely in the cat probe hole. Will it be any cooler 2ft up at the elbow? Another option is to run a smaller load and pull it out once the cat is active. It would be nice to see what's happening when it normally produces creo but that is usually in the medium or high range. Second option is to leave the tip up a few inches to keep the barb cooler. Last, I could make a new 1/4" hole in the pipe but I'd have to go find a large sheet screw to fill it.

It's a silicone hose rated for about 500°F

Yeah that hose probably wont survive long since it attaches so close to the magnet, thus the stove. If it attached 6-12" out from the stove, it would probably be OK...since there is no hot air being pulled through the tube...only heat transfer through the metal.
A test hole up in the pipe would surely be cooler...the hole can easily be plugged with a lag bolt...even a standard machine thread bolt will fit nicely if the hole is the right size...IIRC a 5/16 NC bolt fit nicely in a 1/4 hole. A self tapping bolt would probably make it even easier to start the bolt in the hole.
http://www.shender4.com/thread_chart.htm

 

[Highbeam]

Right. The BK gauge goes from 500-1500°F on active?

So this fits nicely in the cat probe hole. Will it be any cooler 2ft up at the elbow? Another option is to run a smaller load and pull it out once the cat is active. It would be nice to see what's happening when it normally produces creo but that is usually in the medium or high range. Second option is to leave the tip up a few inches to keep the barb cooler. Last, I could make a new 1/4" hole in the pipe but I'd have to go find a large sheet screw to fill it.

It's a silicone hose rated for about 500°F

Yes, it will be much cooler 2 feet up the pipe. I measure internal flue temps 18” up the flue and see up to 1000 degrees at high burn, and less than 400 at low burn all with a 1500 degree cat. The probe hole is right there at the cat!

You want to test at high burn to verify that you meet the spec. Then for your own testing at lower rates to verify a low pressure in the firebox at all times.

Good stuff.

 

[maple1]

You could add on some metal pipe to that with a compression union.

 

[moresnow]

My Stt. Next to the probe hole can exceed 600f. Rubber hose....um.
Id be testing up in the pipe. Away from the probe. Seems like checking up beyond the stove in your venting system makes better sense anyhow?

 

[ValleyCottageSplitter]

Yes, pipe probably makes more sense. Would be nice to know the exact pressure right at the probe hole since that's where vapor may be emitted. There's not one single pressure throughout the whole interior volume. There is a large metal plate right behind the cat probe that likely causes a local inc in pressure as the flow hits the plate.

 

[DBoon]

Since you are an engineer and you know what wood species you are using, you might want to use a multi-meter to do a better, more accurate check of the moisture content of your wood. See https://hearth.com/talk/threads/using-a-multimeter-to-measure-wood-moisture-level.40033/ . It easy to do, and you might have a multi-meter already.

I personally have not used one of the ~$20 moisture meters, so I can't vouch for or dispute their accuracy, but they do make assumptions about wood types and I also find it hard to believe that most people really push the moisture meter probes as far as recommended into the wood split.

I'm considering a BK Ashford, so I've been following the thread. I would say that I would not rule out moisture too high in the wood as one of the possible causes of your creosote smell issues.

 

[begreen]

I'm considering a BK Ashford, so I've been following the thread. I would say that I would not rule out moisture too high in the wood as one of the possible causes of your creosote smell issues.

Regardless of wood moisture, that smell should not enter the room envelope.

 

[AlbergSteve]

Regardless of wood moisture, that smell should not enter the room envelope.

Exactly.

 

[SpaceBus]

Regardless of wood moisture, that smell should not enter the room envelope.

This is what makes me wonder if it is coming back into the house after exiting the flue. Maybe through the perpetually cracked window upstairs?

 

[begreen]

An open window upstairs would likely be exhausting air from the house, but it would create negative pressure on a lower floor.