Oslo draft problem

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flusher17

Member
Hearth Supporter
Jun 3, 2010
53
ADKs, Northern NY
I am still having a lot of trouble cold starting my Jotul Oslo. For about the 10th time this year, I had smoke billowing out the bottom and sides when I tried to cold start this morning. I checked the chimney and the cap and everything is perfectly clear.

It was 18 degrees and no wind. I just can't figure this out. I even ran a heater in the firebox for 10 minutes to start the draft first.

I am starting to think maybe my chimney is too short. I have 15 total feet of Excel 6 inch, with two 15 degree angles. The exit from the stove is straight out the back then an immediate T to vertical. The cap is a little over 2 feet above the ridge of a one story ranch.

Do you guys think I should add another 2 feet? I don't really want to spend 130 bucks if I don't have to, but I will if it will solve this problem. Filling the living room with tons of smoke is getting ridiculous. Thanks.
 
Adding height to a chimney always increases draft. Whether or not this is your only issue in your case, I do not know, but adding more to your chimney will increase draft.
 
You might be able to compensate for the poor draft by using kindling, 1" or less size, and fire starters. Like a Super Cedar or something else.

Those will burn hot with poor draft pulling in fresh air to heat the flue more quickly.

Newspapers on top of kindling burn really hot and fast , this heats the flue up quickly

Plus leave the door cracked as the kindling and fire starter and newspaper burn as this flushes more heat up the flue.

The main idea is heating the flue better and quicker gets the draft a going up the flue before the smoke builds up and smothers your fire.
 
Instead of buying the chimney pipe first, you can just try to extend the chimney with black stove pipe. This is not a solution at all. This is only to see if a taller chimney will solve your problem. With not fire in the stove, on a cold start add 2' of black stove pipe on top of your chimney. Try to start a fire, if it works good immediately you know the solution. But do not leave the pipe up there while you are burning, just have it there for a few minutes on start up to see if there is a difference.
 
I have tried ALL the different starting methods to get the draft going and sometimes(not every time) it just smokes out into the room.

I may try the 2 feet of cheap pipe method first. Thanks for that idea. I hope I can return the black pipe after.
 
Before you attempt to start a stove that the chimney is back drafting try to get the draft going the right direction first or as you know it can have very bad consequences. Before trying to warm up the chimney:

1) Crack open a window on the same floor as the stove.
2) Make sure ALL venting devices in the house are off. Bath fans, range vent, dryer, power vented furnace, boiler, water heater, etc.

If it is back drafting placing a heater in the stove very well may not get the draft going the right direction as the cold air coming back down the chimney will just blow the warm air back out of the stove. You may need a little more direct brute force than that such as: stealing the wife's hair dryer and sticking it up in the chimney, heat gun same way, propane torch, shop vac that you can put the hose on the outlet blowing air up the chimney, etc. Next I would try to figure out why it is back drafting as it should not when it is cold out so something is causing it to happen. It could be stack effect if it is in a basement or lower floor of the house, the house is too tight and a venting appliance is drawing the house into a negative pressure, or a wind issue causing a down draft.
 
I just added 3 feet to my previously 15 foot chimney, and it has certainly helped with the draft. I don't do many cold starts, but I was having some trouble with getting fires going quickly when reloading, as well as some issues with that stove puffing. I have 2 oslos so it's pretty easy to compare performance. The one with the longer chimney still does better though.
Here is the link I started on that problem. https://www.hearth.com/talk/threads/lazy-draft.103086/#post-1332655
 
I'm no Xpert but just wunderin how you are starting from a cold stove. I follow Jotuls instructions that came with my stove almost to the letter and have never had a problem. 2 splits, 1 in front, 1 in back. some of last nights windsplitter crumpled up with some small kindlin on top. When that takes off good I add more wood from small to large letting it get going good before adding more wood. All the while leaving the side door open just a cracked just abit. Once the box is full and going good I watch my stack temp and when it gets into the comfert zone and the far looks good I close the side door and let the stove heat. And like someone else said about having a fan runnin in another room, it's pretty easy to create a negetive pressure situation iffn your house is tight.
 
The title of your thread is one respect a misnomer. Stoves don't really produce much draft, flues do.
As mentioned, you probably have a flue height problem.
Insulating the pipe may also help if its not already.
Someone's point about negative pressure in the house is a good one. An outside air supply (aka OAK) would help with that.
 
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I have a similar situation here at my house. I have 15 ' of pipe also with a new pretty tight house. I had smoke coming out the bottom also, smoking out the house, then I read on here to open a window. This little trick worked like a charm, I have not had smoke in the house since! Give it a try........
 
I have an Oslo as well and on occasion I will get some smoke spillage like you describe. I have 23' of Class A so height is not an issue. Basically my limited research has led me to believe the Oslo can be cantankerous when cold starting. With practice I've had fewer smoke spills. I advise you to use a firestarter, I like SuperCedars, small kinling initially, and leave the side door cracked while getting things going. I also use a Mapp gas torch to light the super cedar. While overkill it does introduce some initial heat into the firebox.
 
a couple of things. First 15' straight up is the min. height that Jotul recomends for any of their stove, so having elbows and a tee does bring you under the recomend height. Second what type of cap from Excel did you get? we have found the deluxe cap caused more problems than it was worth on the majourity of stove we instaled. We have always used the regular cap and windsheild. If you have a deluxe cap go up and cut out the band and try that to start before spending allot of money
 
Thanks for all the ideas. I bought the extra 2 feet for piece of mind. I am going to try cracking a window and using more paper and a torch to get it hot-hot quicker. I guess we'll see.
 
I can't help but think your gaskets and or seals are gone in your stove or whatever Jotul uses on their seams.Not your door gaskets but your seamsWhy would a stove leak at anytime.You didn't mention whether or not your door was open but smoke coming from the sides and bottom,seals may be PART of your issue.
 
I can't help but think your gaskets and or seals are gone in your stove or whatever Jotul uses on their seams.Not your door gaskets but your seamsWhy would a stove leak at anytime.You didn't mention whether or not your door was open but smoke coming from the sides and bottom,seals may be PART of your issue.
Most stoves are not anywhere near airtight. Prove it to yourself sometime by capping the outlet and throwing some lit newspaper in the firebox. You'd probably be amazed at how many leaks there are.
Stoves operate under a vacuum created by a flue draft. Air is literally pulled through the stove by the draft.
 
I say the T and 2 angles may still have a part in all of this. My Oslo pipe runs straight up and has never smoked. Many stove installations have some built in "personality" that just has to be learned, and then adapted to.
 
I tried the paper thing and I found it made to much smoke! Get a super cedar or something like this product. I mixed the super cedar with some cedar kindling and this gets the fire going quickly with little smoke.
 
My insert has bypass that allows me to stick a ball of paper directly in the flue and light it up. The 'fireball' will shoot up the flue with sound like a freight train and warm the flue enough to prevent any spillage. Not sure you can do this with the Oslo or not. Also make sure you turn off all vent fans and crack open window like other suggestion.

Last resort will be the draft enhancer like a fan on top of the flue. But that can be pricey.
 
Have you cleaned the flue/stove?
Fly ash is VERY prone to collecting in the horizontal pipe and on top of the baffle. Make sure these areas aren't clogged.
 
I have tried ALL the different starting methods to get the draft going and sometimes(not every time) it just smokes out into the room.

I may try the 2 feet of cheap pipe method first. Thanks for that idea. I hope I can return the black pipe after.

Just get a 3' length of regular galvanized 6" round duct for the test. If it works well you have your answer. No, you can not returned used pipe.
 
Burn 24/7 and no cold starts, no reverse draft situation, which is what you got going on.
Unless not possible, then only other option is extend the stack height. During cold starts, you will most likely still have the reverse draft situation.
You'll have to get the flue warmer somehow, prior to starting the fire. Some have used hair driers, torches etc.
 
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Oh i don't have to cap it,i had a few backpuffs while i was sitting there.lol Just a little by the door and that was pretty much it but he mentioned quite a bit of smoke.I'd check seams.Just to be sure,like i said may be PART of the problem.
 
I think the T, elbows, and horizontal exit makes the chimney struggle with initial draft. I did put an extra 2 feet on the chimney, which will help, but I am going to change my start-up procedure. More paper on top to get it hot quicker, and crack open a window in the room. I started a new fire yesterday and it worked perfectly, so we'll see. Thanks for all the replies.
 
Good to hear that it's working better. Sometimes just a few more feet of pipe can be all it needs. However, if cracking a window consistently makes a big difference, then the issue is negative pressure. An outside air kit will help in that case.
 
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