Woodstove not drawing

Stan in Oly, WA

Well-known Member
A few years ago I had a fireplace insert installed in my living room. It is a Jotul Kennebec, a model which my research had indicated to be efficient, relatively trouble free, and a good performer. Unfortunately, it has never worked well for me. It draws poorly, making it hard to get a fire going, and no matter how hot a fire I get going in it, or how long it burns to heat the stove, chimney, etc., it allows some smoke to come back into the room when I open one or both of the doors. It has done this since the beginning, and I know it is not because of any obstruction.

The stove vents through a flexible stainless steel liner inside the masonry chimney, as required by the local building code. It is about 14' from the top of the stove to the top of the chimney. The chimney cap of the liner is directly on a flue cover/flashing on top of the masonry flue. It is the highest point of the roof, but it is not much more than a foot higher than a ridgeline which is within ten feet, to the north. The other problem is that the fireplace does not have a dedicated source of outside air. In fact, to get a fire started when the fireplace is cold, I sometimes have to open the front door and the storm door. Would I benefit enough by adding a couple of feet of chimney (easy) that I might not have to provide an outside air source (extremely difficult)? Or is there something different that I might try first?

Stan
 
Is your supply air intake clear? It sounds like you are not getting supply air for burning. The unit is designed to draw with the doors closed.
 
Are there any turns, 90 deg, 45 deg,(which is better for draft) ?

Those can be a factor, also how tightly sealed the house is, opening a door or window to establish draft may indicate that.

I have one chimney that is much lower than the middle roof line as there is a 2nd story in the middle of the house, I have one additional clay flue tile above the lower roof, and there are times, depending on wind direction or weather, where I have to establish draft, most times not, but it does happen. I also find that opening the top on this stove, minimally and with the fire towards the back, closer to the smoke pipe, I don't get any smoke coming out, I have excellent draft with some air flow from the garage door, minus start up when the wind is not cooperating, but I cannot open the bottom door, it will let smoke out, just how this one works, so I use it accordingly, and always check for draft before so, I have a Tee at the first 90 with a cap that I can take off, and check with an incense stick, punk stick or anything that smokes.

Turns, the roof line, wind, and air flow from inside may all contribute, they add up from what I can see with these stoves.
 
It is always best to clear a 10' obstacle by 2'. I have also seen that to big of doors will smoke, especially if they open to the top. My next fireplace will have short doors.

Trees can also cause a downdraft.
 
Try adding a additional pipe to the top of the chimney. Then I would make a dedicated outside air intake piped to your stove. most modern stoves are a air tight design and as we tighten up our homes sealing any leaks we are starving appliances that need air to work. It seems your stove works better when you open the doors which tells me it needs more air when you close the doors. I have been involved with installing and burning pellet stoves for the last 10 years and most companies recommend making outside air available for these stoves, The same principle applies. You have to replace the same amount of air as you send up the chimney or it won't work right. A chimney has to be warm before it draws decent. A lot of oldtimes would use wadded up newspapers to make a quick amount of heat to warm up the chimney so it would draw faster. So 3 different ideas to consider.
 
I'd go along with the chimney is the problem. Don't know if it's high enough or the flex hose is causing the problem. For sure if the chimney is not tall enough, you will not get the smoke out the top because there will be no draft.
 
Your installer should have vacuum/pressure gauges to check the draft. I installed an outside combustion air supply to help a gas furnaces draw better without making the house drafty.
 
To me, your discription sounds like you have a lot of leaky doors/ windows which are allowing a LOT of outside air pushing into your home, and rather than having a negative pull/draft on your chimney, you have way TOOO much air entering your house from cracks and crannies. Your top of the line stove is not at falt. Fix your house.
Loren, the Acg.
 
That might be backwards. Stan has to open a door to get a fire started.

A drafty house supplies a lot of air to a stove or furnace to draw up the chimney. Flue dampers were needed to prevent too much inside air from being drawn out through the chimney when the stove was not lit.

Outside combustion air supplies were unheard of in older, draftier houses. After people started sealing up all the leaks, then combustion air supplies had to be added.

A well sealed house can cause a stove to draw poorly because there isn't enough air coming into the house to feed a fire and be drawn out the chimney. A small vacuum can often build up inside a well sealed house until someone opens a door or a window.
 
We have a Jotul in our house, and it works great, at the cabin we have a Drolet, works like yours! Both installations have outside combustion air and metalbestos chimneys. The only difference is the Jotul has double wall pipe from the stove to the chimney, to keep the chimney hotter. That is my thought on your problem, is the SS liner insulated, maybe it's cooling off too much. Also I wonder if a flexible liner restricts airflow, I think it might.
 
(quoted from post at 16:05:59 09/06/14) That might be backwards. Stan has to open a door to get a fire started.

A drafty house supplies a lot of air to a stove or furnace to draw up the chimney. Flue dampers were needed to prevent too much inside air from being drawn out through the chimney when the stove was not lit.

Outside combustion air supplies were unheard of in older, draftier houses. After people started sealing up all the leaks, then combustion air supplies had to be added.

A well sealed house can cause a stove to draw poorly because there isn't enough air coming into the house to feed a fire and be drawn out the chimney. A small vacuum can often build up inside a well sealed house until someone opens a door or a window.

X-2

Dusty
 
(quoted from post at 16:05:59 09/06/14) That might be backwards. Stan has to open a door to get a fire started.

A drafty house supplies a lot of air to a stove or furnace to draw up the chimney. Flue dampers were needed to prevent too much inside air from being drawn out through the chimney when the stove was not lit.

Outside combustion air supplies were unheard of in older, draftier houses. After people started sealing up all the leaks, then combustion air supplies had to be added.

A well sealed house can cause a stove to draw poorly because there isn't enough air coming into the house to feed a fire and be drawn out the chimney. A small vacuum can often build up inside a well sealed house until someone opens a door or a window.

X-2

Dusty
 
Russ,

It's a fireplace insert, so it sits in the fireplace with the outlet almost directly under the chimney. The liner isn't insulated, and I doubt that it angles even as much as 22-1/2 degrees where it starts up into the chimney. I don't remember the diameter of the SS liner but I found the sales receipt and the product number for the liner kit ($250!) begins with 06, so that supports my guess that it's 6". I have a strong hunch that chimney obstruction of any sort is not part of the problem. It's done exactly the same thing since it was brand new.

Stan
 
Stan:

You need to raise the top of your chimney by at least 3 feet. The horizontal airflow across the top of the chimney creates a slight suction (draft); BUT in your current situation the airflow coming up the slope of the roof is disrupting the horizontal airflow (loss of draft) because of the close proximity to the chimney. HTH

:>)
 
My answer to the same problem was to install a fan in an opening in basement wall that pressurizes the house to make the stove have a good air supply, once the stove gets going for an hr or so it doesnt need the fan any longer
 
That would be my bet as well. He mentioned air inlet and flue, and back feed of exhaust into the house. My bet follows yours. He's not high enough over the roof peak on his chimney outlet to vacuum or draw out the exhaust.

Mark
 
Hello Stan in OLy, WA,

You answered your own question! You said that providing outside air seems to work. 6" flex piping to the stove from outside air, not the basement, will solve the problem,

Guido.
 
You need to get chimney 2 to 3 foot higher than the highest point of roof and a good source of in coming air ( air lifts smoke up chimney and if house is to tight she will smoke). I have my chimney 3 foot above roof line and a good air intake and still have the same trouble if chimney and stove are ice cold ( down draft). I put a propane torch in stove and once the top of stove starts to feel warm I pull the torch and start fire and this has worked for me.I only have the problem if chimeny gets cold.
 
Thanks everyone. You've given me a lot of good advice here. I'm going to extend the chimney so that it is at least 3' above the highest point of the roof, and see what that will do. As I stated, adding chimney is a simple matter, while providing outside air (except for leaving the front door open) would be sort of a nightmare. Nightmare solutions always get lower priority at my house.

Thanks,

Stan
 
(quoted from post at 11:10:25 09/07/14) Thanks everyone. You've given me a lot of good advice here. I'm going to extend the chimney so that it is at least 3' above the highest point of the roof, and see what that will do. As I stated, adding chimney is a simple matter, [b:07942fbb34]while providing outside air (except for leaving the front door open) would be sort of a nightmare.[/b:07942fbb34] Nightmare solutions always get lower priority at my house.

Thanks,

Stan
always have a window a crack open when the stove is burning.
Cheap, simple and effective. :wink:
 
Hello ss55,

YOU GOT IT!

My house is so tight that even The furnace, and hot water heater draw outside air as well. If I forget to open the outside air and light a fire, my smoke alarm goes off!. MY fireplace has a flue barely higher then the peak..............NO PROBLEM! I reply to you because you seem to get it........


Guido.
 
Hello Dusty MI,

Yep X2! A Picture is worth How many words?

Guido
a168288.jpg
 
Hi, Open a window for a few minutes until the fire gets burning. Then you should be able to close the window. Your house is too air tight. Mystove has the same problem at times. Cheers, Murray
 

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