# Down draft issues - woodstove



## kenmac (Feb 26, 2009)

is the vent the same size as the outlet on the stove ?? Venting looks good from outside. Neg. draft in the home will csuse drafting issues. Exhaust fans , etc, will pull against the nat. draft effect of the heater. If you have any windows in the same room as the heater. Open a window & try using the heater


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## Fantastic (Feb 21, 2011)

kenmac said:


> is the vent the same size as the outlet on the stove ?? Venting looks good from outside. Neg. draft in the home will csuse drafting issues. Exhaust fans , etc, will pull against the nat. draft effect of the heater. If you have any windows in the same room as the heater. Open a window & try using the heater


I'm not sure what you mean? So I took a pic of the stove(if that even helps?)

I've tried opening the window and windows as well as the doors. One time it started to vent normally (as in up not down) but then changed and my house filled with smoke! Check the pic


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## Artco (Sep 23, 2010)

Is that a damper on the pipe attached to the wood stove? Is that pipe clean? Sometimes creosote will build up on a damper and plug the pipe.
Is there a cleanout tee after the pipe goes through the wall and makes the turn to the roof? If yes see if it is clean if no you need to install one with a removable cap for cleaning.
Is the cap on the top designed for the material you are burning it may not be correct to naturally vent off the flue gases. 

When i had a wood stove i had to light news paper in the burner box to start a natural draft because the all fuel pipe when not burning gets really cold and has a tendency to smoke before the fire gets hot enough to start the natural rise of heat (draft) through it. (when its cold air drops)

there is also problems later on when the wood started to burn out and the flue started to get cold again it would loose the natural draft and cause the stove to start smoking and smelling in the house.

You may need to install a draft inducer if you don't continually feed the box with fuel.

Another thing i had to do was install a make up air pipe next to my oil burner. I noticed when the burner would fire it requires make-up air and it gets it from where ever it can and down that flue was the easiest path.
I hope some of these ideas help you.


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## beenthere (Oct 11, 2008)

From the pics, its high enough. As above, are you sure your damper is staying open?

Since that flue length outside is so long, it takes a lot of heat to start and keep the draft up. Once draft is established, don't throttle the heat down. See if it maintains draft then.


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## Jackofall1 (Dec 5, 2010)

Beenthere makes a very good point, as all your stack is outside it will cool down so quickly when the fire get lower, this would demand constant tending, I bet if you insulated the part from the point it exits the house to the underside of the eave it would improve dramatically. 

This would be a bigger job than you may want to do, but I would think it would sure help if not cure the problem. 

Box in the riser, insulate and add siding, I don't know if power venting is even an option.

Mark


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## Fantastic (Feb 21, 2011)

I've tried burning a chunk of cardboard as it gets hot quickly to start the up draft but no luck I've even put a small electric heater inside the stove for 30 mins on high to see if that would work but it didn't.

I had a chimney sweep here to clean thinking it was dirty/clogged but it was virtually spotless. He actually only charged me for half as it was so clean. 

Is it possible the trees to the west/right (in pic#1) are causing a down wind that hits the chimney causing the down draft? Wind comes from that side.

And in pic#2 I labelled what somethings are on my stove to clarify.


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## Artco (Sep 23, 2010)

Try removing the cap temporarily and see if that resolves the smoke.
You may need a different type cap.


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## Jackofall1 (Dec 5, 2010)

I'll bet it will work fine when it warms up outside, there is just too much surface area to heat up on that flue before it starts to draft.


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## Artco (Sep 23, 2010)

Jack--you are right, i had the same problem, but removing the cap and trying it may work. 
If he is lighting cardboard and not actually putting the cardboard or paper directly in the flue pipe where it connects to the furnace, you have to reach in and stuff the flue or it won't work to create a natural draft.
I sometimes had to use almost a whole news paper before it would start drafting good.

My pipe was 6 inch dia. And about 20 feet high (colonial house with wood stove in the basement)

then the other problem is when the fire starts to die out and the cold starts to drop in the pipe the same problem occurs.
Constant feed after it lights is necessary


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## Jackofall1 (Dec 5, 2010)

Artco said:


> Jack--you are right, i had the same problem, but removing the cap and trying it may work.
> If he is lighting cardboard and not actually putting the cardboard or paper directly in the flue pipe where it connects to the furnace, you have to reach in and stuff the flue or it won't work to create a natural draft.
> I sometimes had to use almost a whole news paper before it would start drafting good.
> 
> ...


Is your flue completely exposed as the depicted is?


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## Artco (Sep 23, 2010)

It was and then i built a room and part of the pipe was then inside and it did help a little but the slight smoke and odor was always there. I finally got discusted and put in a pellet stove and that worked.
I know the frustration he is going thru.


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## Jackofall1 (Dec 5, 2010)

Yes, years ago I had a stove, but it was a ranch style home with the flue encased in stone, once the draft was started it would remain, until almost the very end, then the smell of the fire box would drift in, not bad, but you could smell it.

Mark


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## beenthere (Oct 11, 2008)

An electric heater won't make enough heat to warm that chimney up.


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## Artco (Sep 23, 2010)

10/4, he needs to pack the pipe with paper light it, and get a quick fire going. 
A wood stove like this can never be lit if you plan on going out for a long time because when it starts to burn out --same problem comes back.


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## bernieb (Mar 20, 2010)

Try chimneys.com


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## Fantastic (Feb 21, 2011)

Artco said:


> It was and then i built a room and part of the pipe was then inside and it did help a little but the slight smoke and odor was always there. I finally got discusted and put in a pellet stove and that worked.
> I know the frustration he is going thru.


What made the pellet stove work?


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## Artco (Sep 23, 2010)

internal forced draft motor


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## pyper (Jul 1, 2009)

You might want to ask your question at Hearth dot com. There are a lot of people there who really know stoves. I'm not one of them, but here are some ideas running through my head:

That chimney on the outside of the house is double wall insulated pipe, right? Feels solid if you thump it? Usually you have problems with chimney's not drafting because they're A) too short, or B) too cold (not insulated). But if that's insulated pipe, then you don't seem to have either problem. 

On your picture you label the thing on the stove pipe as a "thermostat." Did you really mean thermometer? As in something that's just stuck on the pipe? If there's something inside the pipe there you may have found your problem.

My stove only has about 10' of chimney (plus six feet of stove pipe) and the draft is excellent.

Your two 90 degree bends _are _hurting you. I don't see the trees making any difference -- it's not about wind, it's about warm air rising. It doesn't seem like adding another section of chimney would help dramatically, and you would probably need to support it (three steel wires). 

If you have cold air dropping down the pipe, then were is the warm air going that it is displacing? Opening the windows will probably aggravate your situation, because the heat in the room will rise out of them, and suck more cold air down the pipe. 

What do you use to start your fire? Next time start one with a lot of good, dry kindling. The idea being to get as much heat with as little smoke up the chimney as quickly as possible. 

Where does the smoke exit the stove?


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## Jackofall1 (Dec 5, 2010)

The insulation in "A"-vent is an 1" air space, the flue piping is not packed with insulation. This is why the chimney can't get hot enough to start the draft.

Mark


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## Artco (Sep 23, 2010)

The pipe outside looks like "all fuel chimney" to me. The pipe when not being used gets just as cold as it is outside.
If the pipe is on the north side in the shade it stays cold. The higher the pipe the harder to create a draft.
All fuel chimney has insulation inside and is very heavy and i believe only comes in 30" lengths.


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## beenthere (Oct 11, 2008)

What size is the chimney, and what size is the stove pipe?


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## pyper (Jul 1, 2009)

Jackofall1 said:


> The insulation in "A"-vent is an 1" air space, the flue piping is not packed with insulation. This is why the chimney can't get hot enough to start the draft.
> 
> Mark



Mine is insulated. My chimney has an inch of mineral wool between two layers of steel. It stays cool to the touch, even when there is a raging fire burning. According to this guy, they all are:

http://www.inspectapedia.com/chimneys/Class_A_Chimneys.htm


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## Artco (Sep 23, 2010)

He has not said what type pipe he has installed. It may be the insulated pipe.


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## HVACDave (Oct 16, 2007)

Do you have another chimney in the house? Is it higher than this one? They will often work against each other if you do.


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## kenmac (Feb 26, 2009)

If he comes nack . I would like to know if it smokes up the house with the stove doors open or with doors closed or both


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## Fantastic (Feb 21, 2011)

pyper said:


> That chimney on the outside of the house is double wall insulated pipe, right? Feels solid if you thump it? Usually you have problems with chimney's not drafting because they're A) too short, or B) too cold (not insulated). But if that's insulated pipe, then you don't seem to have either problem.


Yes. Double wall insulated.



pyper said:


> On your picture you label the thing on the stove pipe as a "thermostat." Did you really mean thermometer? As in something that's just stuck on the pipe? If there's something inside the pipe there you may have found your problem.


Yes, thermometer. It's a magnetic one stuck on the pipe.



pyper said:


> What do you use to start your fire? Next time start one with a lot of good, dry kindling. The idea being to get as much heat with as little smoke up the chimney as quickly as possible.


I used very dry cedar and cardboard. 



pyper said:


> Where does the smoke exit the stove?


Through the back and through the damper.


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## Fantastic (Feb 21, 2011)

HVACDave said:


> Do you have another chimney in the house? Is it higher than this one? They will often work against each other if you do.


Yes. There are 3. One for the furnace and hot water heater(oil) and the 3rd probably doesn't matter as it is for a propane furnace in the garage.


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## Fantastic (Feb 21, 2011)

kenmac said:


> If he comes nack . I would like to know if it smokes up the house with the stove doors open or with doors closed or both


Both.


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## beenthere (Oct 11, 2008)

And the size of the chimney is?


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## Fantastic (Feb 21, 2011)

beenthere said:


> And the size of the chimney is?


Oh yeah forgot that... Size as in the hight or the diameter of the pipe?


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## beenthere (Oct 11, 2008)

The diameter, inside diameter.


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## Fantastic (Feb 21, 2011)

beenthere said:


> The diameter, inside diameter.


Outside diameter: 10"
Inside diameter: 5 1/2"
Thickness of insulation: 2 1/4"


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## beenthere (Oct 11, 2008)

The pic of the stove, makes the stove flue look like 6", and like it goes into a larger flue/crock then 6".

Are you sure its not a blockage in the stove itself.


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## pyper (Jul 1, 2009)

beenthere said:


> Are you sure its not a blockage in the stove itself.


That's what I'm wondering about -- perhaps a broken lever or something. My stove will fill the house with smoke if I (or my wife...) builds a fire without opening the bypass.

Given the dimensions of the exterior chimney and the shape of the cap, it might be Selkirk triple wall pipe (incorporating both mineral wool and an air space). That's a good piece of material -- given that you had a chimney sweep look it over, I think you can rule out anything outside the house as the source of the problem.

Did the sweep disconnect and inspect the stovepipe inside the house?


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## Fantastic (Feb 21, 2011)

pyper said:


> Did the sweep disconnect and inspect the stovepipe inside the house?


Yes. Pulled off all the pipe inside and of course the cap... Spotless!!


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## Fantastic (Feb 21, 2011)

How would I check the stove for a blockage? 

And if the stove had a blockage wouldn't that stop the down draft as well? Meaning I wouldn't feel any draft?


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## beenthere (Oct 11, 2008)

A blockage would restrict flow, but not stop it. It could restrict it enough that the heat doesn't draw up enough to prevent teh fire from heating up the chimney enough.


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## Artco (Sep 23, 2010)

ONCE YOU GET THE FIRE BURNING DOES THE SMOKE STOP COMING OUT OF THE STOVE.

IS THERE A DAMPER ANYWHERE IN THE STOVE? iF YES MAKE SURE IT WORKS AND VISUALLY SEE IF IT IS OPEN.

IF YOU GET SMOKE IT SHOULD JUST BE FOR A SHORT TIME THEN IT SHOULD CLEAR AND YOU SHOULD SEE A GOOD FLAME IN THE WINDOW.

CHECK THE GASKETS AROUND THE DOOR AND LOWER DAMPER, MAKE SURE THEY SEAL TIGHT WHEN THE DOOR LOCKS SHUT.


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## Fantastic (Feb 21, 2011)

Artco said:


> ONCE YOU GET THE FIRE BURNING DOES THE SMOKE STOP COMING OUT OF THE STOVE.
> 
> IS THERE A DAMPER ANYWHERE IN THE STOVE? iF YES MAKE SURE IT WORKS AND VISUALLY SEE IF IT IS OPEN.
> 
> ...


The smoke never stops coming out. I've had to put the fire out as ALL the smoke comes in.


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## Artco (Sep 23, 2010)

Are there fire bricks inside the stove?
Can you take a mirror and look up the flue?
When you look inside the stove can you see the flue entrance?
If there are fire bricks inside maybe one is broken or loose and has fallen to partially block the flue exit. I knew someone who was transporting a stove similiar to yours and when he set the stove , looked inside and a fire brick had fallen out and was laying in the bottom.
What condition is the inside liner?
Did you buy the stove new?
I know you don't want to spend a lot of time running around while it is smoking but maybe you could have someone look to see if smoke is exiting the top cap.


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## jdherville (Apr 7, 2011)

*Back Pressure*

With a flue system it is ideal to not have too much length above the roof as the flue will take longer to warm up. Pockets of cold air in addition to the heavy cold air above it are significant factors in causing back pressure. A flue should be as straight as possible and also best to have as little joins or extensions as possible. The exhaust should be expelled with as little obstacle as possible. I am involved with a chimney cowl in New Zealand called a FlueCube, conceived/ invented by electrical engineer Neville D'Herville. It has no electric or moving parts and is effective by due to its shape. I can only say that it may be worth reading about. The testimonials from those who have it installed are encouraging towards the atmospheric problem of down draft. Rather than trying to compete with the heavy cold air it integrates it into how it functions, compressing and combusting unburnt particles, allows a steady vacuum inside the flue, easier light-up, faster to get the appliance radiating at optimum heat and no more smoke inside the room. It's current maximum size is designed to fit a 150mm/ 6 inch flue. Smaller sizes are available but larger ones are still in the trial stage.


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## beenthere (Oct 11, 2008)

Fantastic said:


> The smoke never stops coming out. I've had to put the fire out as ALL the smoke comes in.


Make sure all appliances that exhaust air are off, and try using the wood stove again.

If your attic access is from inside the house, make sure its sealed and not drafting warm air out of your house.


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## Fantastic (Feb 21, 2011)

Sorry I've been away for a bit..,

Ok, take a look of the pic I added...

IVE GOT UP DRAFT!!!

The weather today was sunny and about 9 degrees (Celsius) The chimney was in full sunshine. 

It looks like the outside temp is going to be my issue?? 

I am going to call a local pro to come and assess my set up and see what he recommends.


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## Jackofall1 (Dec 5, 2010)

Go back and read post #5 & #6 if an expert doesn't arrive at the same conclusion I would be surprised.


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## yuri (Nov 29, 2008)

I would tend to agree. If you box it in then you need a zero clearance chimney, need to check with the bldg code as to how to do it and the ins company. Do it wrong or not to code may void your house ins. Not sure why people want to burn wood. Mom had a woodstove in the basement and the HUGE increase in house insurance payments (they charge a lot more due to the increased risk of chimney fires) negated any fuel savings. With a 94% efficient Lennox Pulse furnace or any other over 90% efficient furnace it did not pay to burn wood. Good for cosmetic purposes but a sealed combustion direct vent gas stove or fireplace does the same job and is reasonably combustion efficient. Check with your ins agent to see if your premiums are higher and I hope you told them you have one. Omitting that and having a fire later may void your insurance.

I imagine if you burn a LOT of wood and don't mind doing a lot of stoking and cleaning etc etc and get free wood it may be worthwhile but for the occasional use I doubt it is. Too much hassle for me. They even have remote controls for high end fireplaces, my kind of livin.:yes:


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## bernieb (Mar 20, 2010)

Not meaning to criticize the owners work, as it all looks neatly done, but I'm looking at the overall picture, comparing home value of finished product of a built in fire place verses what the owner has. Maybe just a outside masonary chimney, with a flue liner. I realize btu's from each log has to be considered. Been out of touch with labor prices so.........


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## Fantastic (Feb 21, 2011)

yuri said:


> I would tend to agree. If you box it in then you need a zero clearance chimney, need to check with the bldg code as to how to do it and the ins company. Do it wrong or not to code may void your house ins. Not sure why people want to burn wood. Mom had a woodstove in the basement and the HUGE increase in house insurance payments (they charge a lot more due to the increased risk of chimney fires) negated any fuel savings. With a 94% efficient Lennox Pulse furnace or any other over 90% efficient furnace it did not pay to burn wood. Good for cosmetic purposes but a sealed combustion direct vent gas stove or fireplace does the same job and is reasonably combustion efficient. Check with your ins agent to see if your premiums are higher and I hope you told them you have one. Omitting that and having a fire later may void your insurance.
> 
> I imagine if you burn a LOT of wood and don't mind doing a lot of stoking and cleaning etc etc and get free wood it may be worthwhile but for the occasional use I doubt it is. Too much hassle for me. They even have remote controls for high end fireplaces, my kind of livin.:yes:


I've been toying with the idea of putting in a propane fireplace as I've already got a tank for a propane furnace in my garage. that will be down the road a few years though, for now I want this to work to get a lot of use out of it. I've got about 3/4s of an acre of standing timber on my property so wood come cheap. I've also got a friend who is an arborist and gives wood away as he can only take so much to his yard to sell.


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## Fantastic (Feb 21, 2011)

bernieb said:


> Not meaning to criticize the owners work, as it all looks neatly done, but I'm looking at the overall picture, comparing home value of finished product of a built in fire place verses what the owner has. Maybe just a outside masonary chimney, with a flue liner. I realize btu's from each log has to be considered. Been out of touch with labor prices so.........


The fireplace came with the house when I bought it. I didn't put it in. Not sure what the costs would be in doing that but I'll ask when I get the pro in to have a look.


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## Fantastic (Feb 21, 2011)

Greetings again!!

Have not had a pro in yet but have been doing some investigating with family and friends who have wood stoves and experienced some draft issues.

Found a couple friends put this in

http://www.tjernlund.com/retail/auto-draft.htm

After doing so they had no more issues with the down draft. 

Anyone have some knowledge on this type of unit they would like to share? Good or bad? 

I like this option if it will work(Ill ask the pro) as its something I can do myself and looks very easy to do as well. :thumbsup:


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## Artco (Sep 23, 2010)

That is what i had suggested in # 4 "a draft inducer"


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## Fantastic (Feb 21, 2011)

Artco said:


> That is what i had suggested in # 4 "a draft inducer"


Yes you did! I didn't make the connection to a powered fan at the time I read your post?!? 

Do you use one of these currently?


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## Artco (Sep 23, 2010)

No, i do not have any wood stoves.


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## Ed in SoDak (May 3, 2011)

Our wood stove's pipe went through the wall like yours with two 90º bends. It never drafted well until I routed the pipe straight up through the ceiling and attic. That would be hard to do from the basement.

Does this stove have a catalytic gizmo in the pipe? If so, that might block off draft. 6" pipe may be a bit on the small size.

-Ed


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## Fantastic (Feb 21, 2011)

Ed in SoDak said:


> Our wood stove's pipe went through the wall like yours with two 90º bends. It never drafted well until I routed the pipe straight up through the ceiling and attic. That would be hard to do from the basement.
> 
> Does this stove have a catalytic gizmo in the pipe? If so, that might block off draft. 6" pipe may be a bit on the small size.
> 
> -Ed


I'm not sure? Where would I look to find this catalytic gizmo you speak of?


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## Ed in SoDak (May 3, 2011)

It's been a few years, but we went shopping for a new stove and most of them had a catalytic thing directly on top of the stove itself at the pipe flange. Once heated enough, it would react with unburned gases from the stove and finish burning them. 

It did not "kick in" until flue temps were high enough. In your case, it sounds like your stove never gets very hot, as it smokes too much to ever get close to operating temps.

Basically, the thing was a honeycombed ceramic disk or slab that sat right in the flue opening. You may be able to spot it or feel it from inside the firebox or you may have to remove the pipe to see it.

Not all stoves have it, but it looked to me like it blocked a lot of the flue opening. We burn our stove fairly low, so I doubted if this gadget would be any help at all to me.

With a stove that's operated mainly at low temps since you can't get it to burn correctly, this gizmo, if your stove has one, would likely be sooted up and maybe almost blocked.

Sometimes there's a "smoke shelf" in the top of the stove to keep flames from going directly up the pipe. This may obstruct the view up the pipe from inside, and it's possible the shelf is plugged or obstructed itself. 

What is the function of the stove control marked "damper?" Does this control the air inlet or the smoke exit? It could be levered to operate in reverse of what may seem the logical place. I suppose you've tried it in both positions, or in the middle to start with, but it should show that it's working by increased air flow and burn rate or stoppage of same.

It might be interesting to get a check of the relative draft at the stove door, then slightly separate the pipe from the stove enough to check draft at the pipe to see if the pipe alone is drafting more than when connected to the stove.

Someone suggested removing the cap. There's designs of caps that help in odd draft situations. A screened cap may plug up easily and will restrict flow even when clean if the openings are too small.

I hope I haven't repeated things suggested earlier in the thread. If so, call it times two!  Lack of good draft in a stove can be a real pain, I've dealt with it myself. I hope you get it sorted out!

-Ed


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## BigJim (Sep 2, 2008)

I don't remember if I read all the posts or not so if what I suggest has been posted please just disregard. From what I am seeing your chimney pipe is larger than the pipe coming from your heater. This will cause a stove not to draw well unless there is a larger fire, a smaller fire just will not draw as there is not enough heat to make it draft well. One more thing is be sure to build a large fire when you fire it up for the day as that will burn the creosote out of your flue. If I am repeating information already posted please overlook me.


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## Fantastic (Feb 21, 2011)

So it's been awhile and I have good news.... Turns out I need to open a specific window to get the cooler air in to help push the hot air up.....

The window on the left(when looking at the pic of my rec room filled with smoke) drops cold air right into the front of the stove. The window on the right draws air out of the house?? Odd I know!!

Here's what I did... First I filled the bottom of the stove with balled up paper(20 pieces) then laid my kindling over top of the paper cris crossing them. Then I opened the window and lite the paper in several different spots. It began to draw instantly!!! 

The only issue I've noticed since is when the furnace is on while I'm lighting the fire I get a very small amount of smoke being pulled into the room. But the fire still draws very quickly. 

This was a head scratcher on my end. 

Thanks for all your input!!!!!!!

Ahhhhh nice and toasty by the fire now a days lol


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