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Woodburning stove poor draw

Discussion in 'Plumbing and Central Heating' started by lonspwi, 8 Apr 2012.

  1. lonspwi

    lonspwi

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    I've owned a Dovre Astroline 3cb stove for over 2 years now, and i'm not that impressed with it's performance. Sure, it looks nice, but the biggest problem i've always had is it's problem with adequate draw.
    I've since fitted a liner to the chimney (properly packed out with micafil), fitted a spinning cowl (as advised) but to no avail, the draw is still very poor, even with a chimney of over 12 metres. I can still get a fire going, but if it is'nt attended to, it just goes out ! I'm using proper seasoned timber, bone dry.
    I'm beginning to think there is a problem with the stove itself. Unfortunately the manual supplied is very poor and doesnt have an exploded diagram of parts.
    I've experemented with the ash pan recently. At first i thought the pan was'nt fitting correctly because it doesnt slide fully in, but i've since believed this is it's correct position. The air for combustion is drawn from under the stove and is distributed between the fire bed port and the air wash system. I though if i disable the air wash system, more air will be drawn through the fire bed port hence through the burning fuel. I used aluminium tape to block off all gaps between the ash pan and body of the stove, which effectively forced air to be drawn only through the burning fuel. The result was amazing. I finaly have a glowing fire, burning exactly as i would expect without going out, producing plenty of heat and controlable via the primary air slide.
    Obviously this is not supported by the manufacturer, nor is it a permanent solution, but it seems to work. My next move is to contact Dovre to ask if there is either parts missing from my stove, or to suggest a solution.
    Does anyone else have this problem ?
     
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  3. DeltaT2

    DeltaT2

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    By the very nature of the air wash system they can be very poor at drawing. I've known a few that the home owner uses a blow lamp up the flue before attempting to light them.

    Reminds me of the late 70s early 80s, everyone in rural ares thought they'd go all continental 'Swiss Chalet' & get log burning cookers/boiler to heat their home, f.cking things were a nightmare to get to draw on twin skin flue systems................And you think 'greenwash tree hugging' is a new thing............. :LOL: :LOL: :LOL:
     
  4. lonspwi

    lonspwi

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    Thanks DT2, you're the first person to actually suggest what i've suspected all along; the draw is compromised by supplying air to the airwash system.
    Other stoves i've had experience with, that dont have the flash glass areas to see the flames and dont have airwash, work just fine. My next door neighbour has exactly the same problem with his airwash stove, but his open fire works perfectly just as they have done since our houses were built in 1920.

    Thanks again.
     
  5. dcawkwell

    dcawkwell

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    Only good place for all these wood burn stoves is metal recycling.
    People aren't going to save the planet burning bits of wood.
    Leave it there looking pretty and unused or do the right thing and get
    a nice gas fire. Press the button instant heat no mess no fuss.
    It just works.
     
  6. Corgigrouch

    Corgigrouch

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    Sigh....Gas fires...Welcome to the 1970's.....
     
  7. Corgigrouch

    Corgigrouch

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    Is the ventilation tube from outside free and clear of debris/ kinks in it? Is the ventilation large enough? for the output of fire?
     
  8. lonspwi

    lonspwi

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    I have a pipe supplying air directly from outside. I have also opened the vents to supply air from inside the house. Doors open, windows open, i've tried to increase ventilation as far as i can but still the draw problem persisits.
     
  9. Corgigrouch

    Corgigrouch

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    Have you tried to disconnect the ventilation pipes and run the fire with the windows open to see if it improves your issue? If it does then it is a ventilation issue By the way, the permanent ventilation must be permanet and not closable or with a flyscreen...
     
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  11. lonspwi

    lonspwi

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    No, but with this particular stove, there are plates covering vents underneath, which can be closed when using outside air. I have opened these vents in addition to the pipe supplying air to the stove from outside. The pipe supplying air from outside is fixed in place, but i can put my hand through it to the stove, There are no obstructions.
     
  12. Corgigrouch

    Corgigrouch

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    Ok, then assuming that the flue is properly sized and installed, 600mm before the first bend and no 90 degree bends then I too would be looking at an issue with the airwash system and would be speaking to the importer... Seems that the airwash on these is a bit of an afterthought... This fire should have a permanent air supply that cannot be closed so if you had a supply that could be closed off, then I would want to fit a permanent non closable vent to allow for the fact that you close your vent...
     
  13. FiremanT

    FiremanT

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    ... This fire should have a permanent air supply that cannot be closed so if you had a supply that could be closed off, then I would want to fit a permanent non closable vent to allow for the fact that you close your vent...[/quote]

    I think wth this stove, the supplied direct vent is always open, and you don't need an external suply. I think the OP does have an external vent and it is these that are closable, but as they are not actually needed it isn't a problem.

    I Think I am right i all that.
     
  14. lonspwi

    lonspwi

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    The stove is shipped with metal plates that can be bolted on if external air is supplied. Air supplied to the stove is not a problem, regardless of the configuration, with plates installed or not, the draw is still inadequate with the airwash system in place.
    As a further test, i have run the stove with the door open and placing a sheet of card covering the aperture which surrounds the fire chamber, hence bypassing the airwash ports. The result is a really strong draw
     
  15. DeltaT2

    DeltaT2

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    C'mon!! If the temperature in the flue is too low it just aint gonna draw!!
    Simples!!

    Regardless of vents, any room is going to have enough passive air to get the stove going, unless it's fitted in a Phonebox??!! Direct outside air is of course going to be detrimental to trying to increase the flue temperature.
     
  16. lonspwi

    lonspwi

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    For clarity, i should have said.

    The stove is shipped with metal plates that can be bolted on, covering the ports which supply air to the stove from its immediate surroundings, i.e. from the room. If an external air suppy is available, then the plates are fitted to stop air being drawn from the room itself, to minimise draughts.
     
  17. lonspwi

    lonspwi

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    I understand about flue temperature. Initialy, I build a large fire with kindling which really gets going, producing plently of flames, only when i have a bed of glowing embers do I place larger logs in the fire.
    Flue temp is not the issue.
     
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