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Oslo Continues To Disappoint.....

Post in 'The Hearth Room - Wood Stoves and Fireplaces' started by Nonprophet, Nov 26, 2010.

  1. ansehnlich1

    ansehnlich1 Minister of Fire

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    good grief!

    you mean you ain't gonna even give us a clue?

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  2. Mad Tom

    Mad Tom Member

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    I will verify your wood. Send me a free cord and I will tell you if it is dry or not. :)
  3. cycloxer

    cycloxer New Member

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    dude, u r leavin us hangin? what was it?
  4. wendell

    wendell Minister of Fire

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    Going to be very curious to see how this ends up. NP's stove sounds quite similar to mine.
  5. Green Energy

    Green Energy Feeling the Heat

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    My thought is it is one of the following:

    -- wood (not as seasoned as he thinks it is - but NP says its 2-3 yrs old)
    -- flue ( not creating a strong enough draft - but NP says he has 20 feet of vertical pipe with no elbows)
    -- something wrong with the stove (baffle out of place, secondary air not getting through burn tubes, etc.)

    I guess NP wants to build the suspense ...
  6. Shari

    Shari Minister of Fire

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    And the answer is.......................?

    Shari
  7. ashpanannie

    ashpanannie New Member

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    Me too. I've never had a stove top thermometer....I just make sure it feels good in here somehow, and it is always possible by simply adding to or cutting back on the wood I stuff in the stove.

    Oh, and I try to avoid making any pipes glow cherry red. If the dogs won't lie down in the same room with the stove, it is probably getting a bit too hot! They are old dogs so that hasn't happened yet. :lol:
  8. Nonprophet

    Nonprophet Minister of Fire

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    Well, I'm not 100% certain that I've solved the problem, but after 2 nights of fires in the Oslo I'm pretty certain that I know what the problem was/is.

    Last year when I was having problems with the Oslo in our Yurt with the marginal chimney that I had (with two 90's and a 4' horizontal run) I felt like the Oslo was starved for air and so I modified the doghouse cover by drilling a few more holes into it so as to allow more air into the firebox (as per the whole EUR/USA cover plate issue). While this did improve things somewhat, I still felt like the stove wasn't getting enough air, especially on startup when I'd have to leave the front or side door cracked or else the fire would simply go out.

    So, based upon advice from another Oslo user here, I put a flat "spacer washer" on each of the two bolts that attach the doghouse cover to the stove between the stove and the DH cover so as to allow even more air to enter the firebox through the 1/8" or so gap created by the washers. It was enough of a gap to allow more air in, but not so wide as to fill up with ash. This change also made a positive difference in how the stove burned, so I left the washers there.

    After posting this new thread, I thought I'd just make sure again that the air channels weren't plugged somehow (it's amazing where mice will build their nests here in the boonies.....) and so I removed the doghouse cover to check for any blockages. I used a small can of compressed air to blow through the chambers. No ash or debris was visible, nor was there any sound of anything moving around in the air chambers. When I put the DH cover back on. I decided to leave the "spacer washers" off.

    Incredibly enough, this (leaving the washers off) seems to have transformed my Oslo from a pig to a thoroughbred! I started a fire shortly after in a cold stove, and within 45-50 minutes had stovetop temps (in the corners) of 640-650 degrees using the same wood and the same chimney, etc.

    Frankly, I'm at a loss to explain how such a simple thing could make such a big difference, but it was nearly the same again last night as the stovetop got up to 550 very quickly (it was 30 degrees outside the first night and only 46 last night) so it would appear that the washers under the doghouse cover were the problem.

    I believe that while they improved air flow with the marginal chimney in the Yurt, once in the cabin with 20' of straight pipe I think the gap under the doghouse so dispersed the air in the firebox that if negatively impacted the draft of the fire. Frankly, if I hadn't experienced this myself I wouldn't believe it--and I would not blame any of you for being skeptical either--but the truth is I had NEVER been able to get our Oslo over 575 (even when stuffed full of KD harwood...) until 2 nights ago when it easily and quickly reached 650.

    So, there you have it. Any thoughts on how two flat washers could make such a big difference in how a stove operates????


    NP
  9. WOODBUTCHER

    WOODBUTCHER Minister of Fire

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    I would believe that, remembering this thread from last year left me scratching my head after all the things you tried.
    I’m glad your F500 is acting like it should, we have 2 Oslo’s/1 Firelight/ 1 F100CB in the family and all 4 can kick the 600 barrier easy with the front air control wide open.
    Keep us posted on how things go!

    WoodButcher
  10. spendaviscpa

    spendaviscpa Member

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    Great that you got it figured out! Just to be clear, do you have the USA plate with extra holes drilled, but no washers? Is this correct? You are essentially using a EUR plate then. I’ve re-read the thread a few times and I just want to make sure I understand your final outcome! Thanks
  11. grommal

    grommal Feeling the Heat

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    I can't explain your startup problems, but there's an easy explanation as to why the stove would burn better once it got going, if those washers were removed. The Oslo has a single air inlet through the outside of the stove - a large round hole on the bottom of the stove near the back. This feeds both the primary air (the doghouse) and the secondary air to the tubes. For a given amount of draft, the more air that comes out of the doghouse, the less air will come out of the tubes, since the draft is doing its best to suck air through both routes, but they are not independent. So, the washers were probably starving the secondary tubes for preheated air by letting too much air out the doghouse. That would make it difficult to sustain good secondary combustion.
  12. Green Energy

    Green Energy Feeling the Heat

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    Glad you got it figured out. I have learned that you want to be careful in modifying equipment. Sometimes it creates more problems than it solves.
  13. cptoneleg

    cptoneleg Minister of Fire

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    I have learned that some folks just don't like being called Dude.
  14. ansehnlich1

    ansehnlich1 Minister of Fire

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    Indeed, unnecessary air continually rushing into the firebox through the doghouse gap could prevent the stove from operating properly. If I were you I'd order up a U.S. doghouse cover that has been unaltered and try that out next, or close the extra holes you drilled in the one you have, maybe by threading a bolt/nut in them, just to try that out and see if it makes any difference.

    I might add, I have to leave the side door open on my Oslo for a few minutes until the thing gets up and going.
  15. jotulguy

    jotulguy Feeling the Heat

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    Leaving the side door is a great way to get a fire going! You can light it and close the front door too....but why wouldnt you want it up to temp faster? The only no no ( if you will) is using the ash pan door for start up air. Otherwise the front or side load doors are great choices to help get it going.
    I also want to add, i would strongly recommend getting a new doghouse cover. It will not only give you better burn times but it will also keep your glass cleaner and make the stove easier to control. Glad to hear you found the issue though....best of luck this winter with the stove!
  16. firefighterjake

    firefighterjake Minister of Fire

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    Glad to hear the Oslo is working out for you . . . it truly is a great stove . . . and your issues last year were quite baffling.
  17. Nonprophet

    Nonprophet Minister of Fire

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    Yes, that's correct. We're using no washers and just the modified doghouse cover with 3 extra holes drilled into it. We bought the stove used, so I don't know if Oslo's come new with both the USA plate and the EUR plate--ours only came with the USA plate.


    NP
  18. Nonprophet

    Nonprophet Minister of Fire

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    Well, that's a pretty good theory, and I think you're on the right track with air being shared as part of the problem. The only issue I see with that theory is that even with the washers in we got good action out of the secondaries (they never seemed starved for air like the lower firebox did) and our glass always stayed nice and clean.

    I had another fire last night with the same results--cold stove to 550 degree stovetop temps within about 45 mins, and then 600+ temps on moderate-sized reloads. It's really amazing to me how removing the washers has made such a difference--the dynamics of the fire as seen in the firebox through the front window have changed substantially and this corresponds with more heat being put out by the stove. I'm still nowhere near shutting down the air 90% and maintaining raging secondaries and 650+ stovetop temps like many other Oslo owners claim, but at least now I know that I can crank this stove when I need to and that was really my biggest concern.

    NP
  19. Nonprophet

    Nonprophet Minister of Fire

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    I might look into buying another doghouse cover, though I must admit it seems to be burning pretty darned good right now. I might try plugging the wholes I drilled with bolts just to try it out and see what, if any, difference it makes.


    NP
  20. begreen

    begreen Mooderator Staff Member

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    I'm really happy this is working better for you now. Try some short bolts in the holes for now. Keep us posted.
  21. grommal

    grommal Feeling the Heat

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    With the current weather conditions in PA, I don't get "raging secondaries and 650+ stovetop" with the air shut down 90% either. I DO get raging secondaries and 450-500 stovetop with the air shut as far as it will go. When it gets colder, and the draft pulls a bit harder, then I think I'll see somewhat higher temperatures, especially with very dry wood.

    It sounds like your stove is performing the way it should now. Lots of folks say they need to leave a door cracked open for a little while on startup. There are a lot of variables in play when starting a fire, so it's no surprise that some folks need to crack a door and some don't. But your earlier reports of the stove basically going out if you closed the door - that's something wrong there.
  22. wendell

    wendell Minister of Fire

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    NP, glad to hear you are getting things figured out. I'm still trying to get my Oslo figured out as I have had many of the same symptoms you describe. I need to leave my side door open at least a couple inches for almost 30 minutes to get things warmed up enough to shut it. I can have an absolutely raging fire with every piece burning, shut the door and have the fire go out in less than a minute. But, I've learned that if i open it back up, let it burn for another 10 minutes or so and shut, it will keep burning and I can get the stove top up to 600.

    I started with 14" of glue and added 3 feet which hasn't seemed to make any difference. Checked the air control and it is working fine. Air supply in the back seems to be clear. In my case, I can get it to burn pretty well but it just takes so long to get there, I keep thinking there is something amiss.

    As someone said in another thread, the Oslo is like a freight train, slow to get going but then a great heat producer. Unfortunately, my Morso has me really spoiled when I can reload and have it shut down 90% in 5 minutes with a flue temp of 1000 °F. I guess that makes the Morso a sports car. ;-)
  23. cycloxer

    cycloxer New Member

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    Now that you have the stove burning the way you want, I recommend just leaving it alone. I think the inspection cover is quite sensitive to the draft of each particular installation. With a weak draft, the EUR cover seems to be the way to go. With a strong draft the USA cover seems to provide better control of the stove.
  24. cptoneleg

    cptoneleg Minister of Fire

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    OOh c---- right after I got my drill out. I was going to drill a few holes in the side.
  25. Green Energy

    Green Energy Feeling the Heat

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    If you mean 14' of flue, that is probably too short for adequate draft - especially on cold starts. The other issue that many people have when they first get this stove is you need dry, meaning very dry (i.e., 15 -20 % moisture content) wood. This was a problem for me last year, but not this year as I have 2 year old (split for 2 yrs). Both inadequate draft and not completely seasoned wood could be contributing to your problem.

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