1. Welcome Hearth.com Guests and Visitors - Please enjoy our forums!
    Hearth.com GOLD Sponsors who help bring the site content to you:
    Hearthstone Soapstone and Cast-Iron stoves( Wood, Gas or Pellet Stoves and Inserts)
    Caluwe - Passion for Fire and Water ( Pellet and Wood Hydronic and Space Heating)

Fixing too much draft...

Post in 'The Hearth Room - Wood Stoves and Fireplaces' started by EJL923, Oct 24, 2012.

  1. cnice_37

    cnice_37 Member

    Joined:
    Mar 24, 2011
    Messages:
    55
    Loc:
    Assonet MA
    First off great thread, and I am watching closely.

    I like to load N/S in the Rockland, I find I can fit more in, no rolling logs onto the glass, and given that I cram more in there, I can extend burn times. A fully loaded box, from 250F temps loaded at night, runs up to 800F and back down to 250F in around 8 hours MAX with coals left to light again. This is using red oak mostly.

    I do agree too much air gets in the box, and the primary air adjustment doesn't matter. I grinded off the bump stop last year, and unless you add tape, the primary air is still open a good 1/2" if memory serves correctly. Haven't played with doghouse holes.

    Helpful Sponsor Ads!





  2. begreen

    begreen Mooderator Staff Member

    Joined:
    Nov 18, 2005
    Messages:
    46,066
    Loc:
    South Puget Sound, WA
    One good solution for tall flues is to downsize the liner to 5.5 or 5". A second solution is to carefully reduce the primary air intake. Before doing this second step, examine how the air control valve actually works and check to be sure that it is not loose or sloppy. If it is, tighten it up. Depending on the air control design, you may be able to slightly move the stove or partially block off the intake. But don't block it off all the way. An eighth of an inch makes a big difference.

    I would not change out the glass. That would decrease efficiency.
  3. EJL923

    EJL923 Feeling the Heat

    Joined:
    Oct 29, 2009
    Messages:
    450
    Loc:
    Western Mass
    The cast iron slider closes off the air all the way once the stop was ground off the slider. How tight that is remains to be seen. There is nothing that can be done to the primary air intake after that. There are small slots just above the door. You might be able to stuff some small gasket rope in there, but it has to be done carefully or it takes away the looks of the stove. its in full view. The only thing i have left is to make the secondary air adjustable. That involves pulling the stove, that should be fun...... If i decide not to pull the stove, in goes a key damper right at the outlet.
  4. OhioBurner©

    OhioBurner© Minister of Fire

    Joined:
    Aug 20, 2010
    Messages:
    686
    Loc:
    Central Ohio
    I dont remember when I said that but it was atleast last winter, and I have forgotten most of the details. And I just started burning this year a couple days ago.

    I've done both the longest splits I could cram in there E/W 20-24" and also 13" or whatever fits in N/S. To be honest I really like the N/S loading, I think I can pack the stove more, and its less hassle loading and easier to split (but more hastle cutting, stacking, carrying). Long splits E/W are a pain, unless they are perfectly straight they take up more room, the door is smaller so you have to put one end in first and have room to put it in further, straighten out, then place. You can never fully load it with pieces that are just barely short enough that way. I broke one of the firebricks trying to cram a long split in there too. I think N/S might burn just a little hotter/quicker, but burn time is probably close since I can fit more in there. The problem with the bigger splits (I mean across, like the 7-8" you mention) is you can only get one layer. A second layer would have to be super small splits. So not sure. Most of my stuff I've cut for this year I just shoot for medium, seems I can load about 4-5 across in 2 layers.

    Did anyone photo the modification of the primary air lever? Maybe there are some in the Rockland thread I forget, havent been on it in a long time.
  5. EJL923

    EJL923 Feeling the Heat

    Joined:
    Oct 29, 2009
    Messages:
    450
    Loc:
    Western Mass
    If you pull out the primary, it will be evident what needs to be modified. I don't have any pics
  6. OhioBurner©

    OhioBurner© Minister of Fire

    Joined:
    Aug 20, 2010
    Messages:
    686
    Loc:
    Central Ohio
    I remember I tried doing that last year I think it was, found some bolts inside the firebox around the area of the slider, but nothing came loose. I didnt want to try to force it not knowing for sure how to do it, or if there are other hidden bolts I didnt see. Might have to try it again sometime, but if it didnt help I'm in no rush to try taking it apart.
  7. EJL923

    EJL923 Feeling the Heat

    Joined:
    Oct 29, 2009
    Messages:
    450
    Loc:
    Western Mass
    There are three bolts, the one in middle top is a little hidden
    OhioBurner© likes this.
  8. EJL923

    EJL923 Feeling the Heat

    Joined:
    Oct 29, 2009
    Messages:
    450
    Loc:
    Western Mass
    I decided to take a break, but im installing a adjusting slide bar for the secondary air as we speak.Due to the surfaces and amount of area i have to work with, i will be able to adjust the air down to 75% shut, and then open up wide open. Theres a give or take, but i want to be able to leave it "stock" if i find there is increasing creosote or something other.
    Savaneiro likes this.
  9. Savaneiro

    Savaneiro New Member

    Joined:
    Nov 7, 2012
    Messages:
    6
    Loc:
    Western NY
    Excellent! Glad to see you went this route. I hope you can snap a few pics so we can see how to do it right. Can't wait to hear about your results.
  10. OhioBurner©

    OhioBurner© Minister of Fire

    Joined:
    Aug 20, 2010
    Messages:
    686
    Loc:
    Central Ohio
    Yeah can't wait to see results! I do remember now thinking about such a mod when someone else did it in an attempt to lengthen burn times... not for the Rockland or this problem at all, but to allow their stove to burn normal (secondaries open fully) until past the off-gassing stage and into the coaling stage then close the secondaries (since its just pulling in cold air at that point, cooling the firebox and exhaust gases and wasting heat I think). Such a control would be quite useful for helping a runaway too. But with the secondary air intake not really accessible on the Rockland, I dismissed it. It would be nice to see how you rig up controls to be able to open and close it (from in front of the insert I assume). Good luck!
  11. begreen

    begreen Mooderator Staff Member

    Joined:
    Nov 18, 2005
    Messages:
    46,066
    Loc:
    South Puget Sound, WA
    Another option might be to introduce a restriction at the flue collar or flue collar adapter. I would consider this as it requires less fiddling with controls at various stages of the burn. this is important if multiple people run the stove. A 1/4 to 1/3 block welded at the flue collar or stainless pop riveted into the adapter is what I had in mind.
  12. EJL923

    EJL923 Feeling the Heat

    Joined:
    Oct 29, 2009
    Messages:
    450
    Loc:
    Western Mass
    Begreen,
    Would adding this damper section directly to the stove outlet be to code? I have been trying to figure this out. I get confused if it would count as stovepipe or chimney pipe because its an insert. It would not extend into the flue, it will only be the first 4-5 inches above the stove. The stainless liner gets trimmed to fit the new height.
  13. EJL923

    EJL923 Feeling the Heat

    Joined:
    Oct 29, 2009
    Messages:
    450
    Loc:
    Western Mass
    The guy at duravent said it can't be used with inserts, nevermind. Seems cautious but ill follow.
  14. EJL923

    EJL923 Feeling the Heat

    Joined:
    Oct 29, 2009
    Messages:
    450
    Loc:
    Western Mass
    I have the slider installed for adjusting the secondary. I will post pics when i get a chance. Haven't had a chance to do much experimenting because i need to refresh myself on how the stove burns regular first. Its amazing when you light up for the first time in the season how you think you need to relearn, then it all pops back into your head.
  15. Dutch

    Dutch New Member

    Joined:
    Dec 5, 2012
    Messages:
    30
    Loc:
    Southern WI
    I have a brand new Jotul F55 Carrabassett with 6' of stovepipe hooked to 16' of class A through a second story. Initially I was very disappointed in how difficult it was to obtain secondary combustion with partial loads. One day while burning lumber cut offs I covered most of the secondary air port to prevent overfiring and was astonished at how much faster the secondaries lit with the port covered. I also noticed easier start ups due to more draw on the primary intakes. In my best judgment the stove seems to operate best with nearly all of the secondary port covered. There is a lot of crevices for the air to leak into even with the port blocked. I am still experimenting and plan to discuss this with my dealer as I find this a little dissapointing.
  16. Dutch

    Dutch New Member

    Joined:
    Dec 5, 2012
    Messages:
    30
    Loc:
    Southern WI
    I hope this helps and that I don't get to far of topic. However, my concern is that this stove would operate incredibly differently depending on how much draft is applied. The stronger the draft the more disproportionate the secondary air becomes. I understand this is how most EPA stoves are designed, but I expected more from Jotul. I feel that a reputable stove manufacturer would design a stove with a well balanced primary and secondary air, and install the damper control prior to both of these intakes.
  17. jotulguy

    jotulguy Feeling the Heat

    Joined:
    Oct 9, 2010
    Messages:
    335
    Loc:
    central Pa
    Dutch, do you have a stove top thermometer? Once the stove reaches 400 on the surface the secondaries with fire off. I am curious why you are having trouble trying to get this to happen and at the same time are concerned about an over fire? the two are on opposite ends of the spectrum. Maybe you could start a fresh thread so we dont hi-jack this one and see if the fine folks here at Hearth.com can help you.
  18. Dutch

    Dutch New Member

    Joined:
    Dec 5, 2012
    Messages:
    30
    Loc:
    Southern WI
    I've been meaning to post review soon, tommorrow possibly. I do feel my situation is very relevant to the OP. I feel we both suffer from too much secondary air. The reason it was difficult to get secondary ignition from a smaller for is because of the massive volume of secondary air "spraying" out of the baffle. When the air is slowed down, given more time to reside in the manifold, I would see secondary ignition at a much lower stove top temperature, and longer into the burn. I would also notice the secondary air extinguishing the primary fire late in the burn cycle.

    On the other hand, as with the OP's scenario, with a hot and full stove, these secondaries would contribute to an overfire. I have never experienced an overfire. I was being over cautious when I decided to block my secondary air intake. It just so happened that this is how I discovered my "underfire" issue. Please let me know if thi doesn't seem relevant to the OP, and also if I an confusing the heck out of you :)
  19. wkpoor

    wkpoor Minister of Fire

    Joined:
    Oct 30, 2008
    Messages:
    1,854
    Loc:
    Amanda, OH
    Its very common for me to see 800. On a pretty full load 12hrs is an easy mark with 16hrs being my all time best. In the last 3 yrs I've seen 800 at least a hundred times. It makes no difference to the Elm. From a thermal stress point of view the Elm has it nailed.
  20. EJL923

    EJL923 Feeling the Heat

    Joined:
    Oct 29, 2009
    Messages:
    450
    Loc:
    Western Mass
    Good info Dutch. I have yet to play around with my slider as im waiting for it to get colder outside for full draft. I have also yet to post pics of my slider adjustment, but will do so eventually, been busy. Keep the info coming
  21. brian89gp

    brian89gp Feeling the Heat

    Joined:
    Mar 15, 2008
    Messages:
    438
    Loc:
    Kansas City
    Different stove, so your milage may vary. I have a Buck 85 that has the primary/secondary air combined and was having an overdraft problem. 6", just shy of 40', insulated on an inside chimney. Even now after getting it more controllable it will regularly run up to 650-700* and it sits there for over an hour with the blower running on high.

    On mine I was able to get it more controllable by tightening up the air intake sliders (combined system, so they controlled both primary and secondary) and by blocking a small 1/4" hole that was permenantly open.

    On my several phone calls with Buck, they suggested that if tightenting up the sliders or blocking the small air hole didn't work then I should look into ways of blocking the flue either by a damper or a permenant restrictor plate.
  22. Dutch

    Dutch New Member

    Joined:
    Dec 5, 2012
    Messages:
    30
    Loc:
    Southern WI
    ELJ,

    Glad to hear were on the same page. What I meant to say earlier is that my secondaries would actually blow out a small fire, prior to my modification. I don't think our situations are identical, our stoves are quite different. However I feel we were both kinda dooped by Jotul's limited testing and poor tuning. I have been using magnets to cover the secondary air intake, but plan to install a slider that I can adjust from the front of the stove. Best of luck to you as you have it worse than I do, due to having an insert. I think you'll see improved results with any modifications.
  23. EJL923

    EJL923 Feeling the Heat

    Joined:
    Oct 29, 2009
    Messages:
    450
    Loc:
    Western Mass
    well youre now the second person who said limiting secondary air has helped the secondaries ignite. I have yet to start my experimenting, but can limit my secondaries all the way to 80% closed.
  24. JTP11

    JTP11 Member

    Joined:
    Oct 14, 2011
    Messages:
    19
    Loc:
    Long Island, NY
    EJL, I've been thinking of a way to restrict my secondaries but make it adjustable. Perhaps using a cable driven slide. Can you share details or photos of your mod?

    Cheers,
    JTP
  25. Bagelboy

    Bagelboy Member

    Joined:
    Oct 21, 2013
    Messages:
    164
    Loc:
    Catskills, N.Y.
    Agree with most here, adjusting the air going into the stove is very important. It can't exhaust, if the intake is stalled. I personally think a good draft is very important. Why not work and concentrate on toning down the intake. When my intake was closed on my Osburn, I was able to find a hole the size of my index finger allowed by the EPA. I have been experimenting with sealing this off, and it has made a big difference!

Share This Page