I have been using a jotul F3 attached to a lined chimney via a T piece for 12mths and its fantastic.
Only problem is its too hot. I only use wood and have put in a blanking steel plate to close off the ashes griddle and the fire burns on a bed of ash very well. On fully open vent the fire absolutely roars and eats wood which is fine for starting the fire, but even on fully closed vent (bar to LHS), the fire is still very lively. End of last winter I changed the door ropes, main door and ashtray door and it has made little difference. Are there other ropes / seals i should replace or is it worth considering an adjustable baffle in the chimney. Our house is quite exposed and the top of the chimney gets a fair draught when the wind blows.. but this is not necessary for a roaring fire.
any suggestions gratefully received. thanks, jon wales.
I was going to try answer you questions earlier but as I don't own one of these stoves I needed to find a little time to find and down load the owners manual. I found the US/Canadian Version.
Explain what you mean by a T piece. I'm wary of assuming what a particular term means in another version of English besides my own.
The manual I downloaded shows a draft in front that can be opened, be sure that that is closed also.
You say you have used this stove for a year. Did you buy it new or used. A year old stove shouldn't need gasket changes. From the manual there is also a gasket between the glass and door. The manufacture mentions furnace cement. This leads me to believe that the joints between the cast iron pieces are sealed with it. This is how cast Iron stoves are sealed, when they are. The problem with furnace cement is that it is brittle and a piece of it can get knocked out of a joint and leak air.
This is quoted from the US manual.
"Other times, chimney height can create excessive draft
which can cause high stove temperatures and short burn
times. Excessive drafts can be corrected by installing a
butterfly damper. If you suspect you have a draft problem,
consult your dealer."
Damper is the North American term for a piece of metal, usually cast. that is placed in the stove pipe and can be turned to vary the draft.
One last Question what kind and size wood are you burning.
thank you very much for you guidance, here's some clarification points:
t piece.. the stove has a rear exit flue which goes horizontally about 4 inches then vertical up the lined chimney, with a cleaning cap directly below the vertical i assume for brushing the flue without disconnecting the stove.
there is a vent on the bottom of the door which is always closed, and a controlling bar on the top on the front for varying draft.. there is still a very fast burn even when this is also fully closed
the stove was second hand, and i assumed a few years old but not sure about this, i only replaced the door seals and omitted the glass seal rope which may be a problem??
the chimney is fully lined with a double skin flexible liner and back-filled with what we call vermiculite (my father and I did the lining job). This meets building standards here. the height is approx 10 metres to the top of the chimney and is (I think) 6 inches diam.
Wood is currently very variable, and I'm still burning a lot of scrap for the house refurbishment.. window frames / door frames and bits of small stuff too, I'm aware that this is not ideal but this problem was evident when I was burning decent hardwood logs last winter too.
Im familiar with the term damper and I'm guessing this is what i need to retro-fit.. to the visible length of the flue in the fireplace recess. Is there anyway of testing for leaks around the glass or elsewhere first?
Given that my query has also been sent to Jotul uk I'm ver grateful for your help because they havent even acknowledged it!
The lack of a seal around the glass may be the cause. To find air leaks I take a stick of incense or something that will smoke and move it around the stove with a fire in the stove. A leak should draw smoke to it. Also try to see the actual draft control that the lever moves to see if it actually is closing all the way. Being used it may be messed up somehow.
I would put a damper in the pipe. I suspect that a 10m well insulated chimney produces more draft than the stove was designed to cope with. As far as I can tell this is a century and a half old design that has been updated and not a true airtight stove. The problem you may have is where to put it. I'd like to put it in the horizontal run just to be able reach it to open and close it and so it doesn't interfere with cleaning the chimney, but 4" isn't enough space. The pipe is close to 6" or the metric equivalent. I have no Idea how far off American and European stove pipe is.
Construction scrap will burn very rapidly and I would not expect the fire to hold for much more than an hour with out having to be refueled.
Hi Jonnieboy - did you get a solution to this?
Funny - I have exactly the same problem, with the same chimney etc.
Only thing I have found that solves it is to put a thin strip of wet newspaper over the vents including the vent slider and it then settles and the secondary combustion works.