8" stove to 6" liner?

[Omahstylin16]

Im sorry guys I know this one has been beaten to death but I'm wondering if I'm just imagining this problem....

Its my first year using a wood stove. I bought a used Jotul #8 non cat front loader with the sundial shaped damper on the door. I had a chimney sweep come and install a liner in my brick chimney for the stove. He told me that because of the size of the existing flue he would use a 6" liner and an adapter to connect to the 8" flue on the stove and that this would run just fine.

Well that was december 10th and I'm still not sure if I'm doing something wrong or the stove isnt drafting correctly. I can get a fire lit pretty easily and it will get hot fast with smoke just about dissapearing very quickly with the damper wide open. However after an hour or so the fire seems to die down and I have to poke it or shift around the wood and coals every 20-30 minutes to keep it burning well, and this is with the damper wide open. If I turn the damper down the fire dies down quickly and im afraid that its going to go out.

It keeps my living room and kitchen very warm if I maintain it this way, but I feel like I'm burning a lot of wood and I only use the stove 8 hours or so a day between getting home from work and going to bed. I have burnt it hot for 4 hours straight and tried to dampen it down to keep it going overnight and will wake up to half burnt cold logs in the morning.

I havent put a damper in the flue because i assumed it would only make the problem worse, and I havent put a temp gauge on the stove yet as it does get very hot when I'm maintaining it.

I'm just concerned because the guys at work tell me that theirs will run overnight no problem and after dampening it down they very rarely have to maintain it at all other than feeding more wood occasionally.

Can you guys offer any tips?

 

[pen]

When you open the door on the stove does smoke pour out? If not, then you at least have a fair draft. If smoke comes into the room then I'd be suspect if your chimney liner isn't in the upper teens in length at least.

How was your wood seasoned? It sounds like you could have wood that has dried on the outisde but not all the way through perhaps? Do you have a lot of rounds and not so many splits? Rounds dry out slower than splits do.

pen

 

[begreen]

I suspect the wood. It sounds like it is not really dry. Try bringing a batch in the house and let it sit out in the open for a week to dry out. If it burns a lot better, this is the problem.

But just to be sure. Can you describe the entire flue assembly, from stove to flue cap in detail? Include details like elbows or tees, and whether this is an interior or exterior chimney.

 

[webbie]

Jotul 8, as I remember, used a 7" flue so the reduction is not as bad as from 8"......
It does not have a vast firebox, so overnight burns on that stove could take some skill...and good wood and good timing.

I think you should use Occams razor to figure out the most likely problem!

That would require the following steps....
1. Take the wood out of the equation by either getting a moisture meter or borrowing some wood from a known source which is bone dry......
2. Use a surface thermometer do you know how hot your stove is......

Sure, we could use the height of the chimney, number of els, if it is front of the fireplace, etc....also, but start with the wood. I suspect a less than perfectly tight venting system also. Make certain the stove top is seated down well (seal with furnace cement also if needed) and that the pipe joints which are exposed are also sealed with cement.

 

[Omahstylin16]

quickly, thank you for the fast responses, I do appreciate the help

the stove is placed in a large brick fireplace in my livingroom, the chimney is an exterior brick chimey. the flue itself starts at the rear of my stove with the 8" collar which is connected directly to the adapter which goes into a T with a cleanout on the bottom and goes straight up the chimney approximately 20 feet to a rain cap

the wood itself is a mix of maple and oak that I cut myself in september of 2009 into 16" lengths and handsplit. it was all stacked by the end of october in my backyard, it was never covered until december 2010 when i started taking from the pile and up onto my screened in porch where it will sit for a week at the most before being burnt. id say 1 out of every 10 pieces is a round and yes they are slow to burn, I tend to wait until i have a hot fire going to add any rounds

there have been a few occasions where ive had 6 or 8 pieces in the house next to the stove for a few days if its been warm out and I'm not burning, I dont recall a noticeable difference in how they burnt but I wasnt looking for one at the time so I may have to try this again

thank you again for the help

 

[Omahstylin16]

webmaster, im going to be going out and getting a stove thermometer either tomorrow or tuesday to check my temps. is a moisture meter something I could pick up locally?

 

[pen]

moisture meters can be found all over the web (such as amazon.com)

Oak can take 2 years to season, so unless you had the perfect circumstances that still could be your issue.

The thermometer never hurts so that you can get a baseline.

Does your fireplace have a block off plate? Or can you look right up the flue next to your liner?

You never said whether or not smoke comes into the house when you open the door either. Is the liner that you installed insulated?

pen

 

[Omahstylin16]

i installed some sheet metal around the liner which cant be removed easily haha

i didnt install the liner myself and I didnt know to ask the installer at the time so I'm not sure if the liner is insulated or not, is this something I could tell by looking at it? there is about 2 feet exposed behind the stove

ive had a small puff of smoke come into the house a couple of times while trying to get a fire started, but usually once its gotten going i dont get smoke in the house

 

[webbie]

the wood sounds ok............especially if warmed up for a couple days....

Are you certain it is 8" and not 7"?

Also, do you have a very tight fitting block off plate at approx the level of the fireplace lintel as per pen and the article below:
https://www.hearth.com/econtent/index.php/articles/making_a_block_off_plate/

If you don't......that could be a BIG part of the problem. Also, check the pipe joints as to whether furnace cement was used......a good test is to hold a lighted match near those joints - if it gets sucked in quick, you are losing valuable draft! Also, if you have an adjustable el or tee where the pipe heads up, this might need sealing also......

Let's hear about that block off plate...or lack thereof.

 

[webbie]

i installed some sheet metal around the liner which cant be removed easily haha

Uh, oh....I'm not laughing........

The entire system sounds leaky...the plate being the single most important part. Think of it this way. Any leaks in the system are like having a hose to your vacuum cleaner with lots of holes it in - if you had this, you could complain about it not sucking well at the other end!

Not only is your draft being lost, but chances are that some heat is going up also......having a tight plate which is as low as possible in the fireplace throat assumes that most heat will flow back out into the room instead of being trapped and sucked up......

I predict that taking care of this will go a long way toward solving the problem......think of that old soul song "tighten up"......

 

[Omahstylin16]

ok you are right webmaster it is a 7" flue

as far as the block off plate goes i installed mine up at the damper height rather than the lintel which the article says is wrong but it is very tight fitting and is sealed with fire caulking and furnace cement

i cant check the pipe joints right now because the stove is hot at the moment

 

[begreen]

Is the horizontal connector from the stove to the tee pitched slightly uphill? It should be pitched upward at least 1/4" / ft.

 

[Omahstylin16]

it does look like it goes slightly uphill but its tough to tell, its only about a foot long

 

[Omahstylin16]

well guys i tried burning some wood that ive had in the living room for a few days tonite and it does seem like i can dial it down and it will stay burning much better. i tried holding a match to the joints in the stovepipe and they seem to be tight.

basically im thinking that this is an issue of moisture in my wood, but i still plan to pick up a thermometer, a moisture measurer, and will more than likely replace my block off plate and reinstall it near the lintel