wood burner no heat

[igotalake]

hi all,

i have searched and not found anything that answers my problem but if i've missed something, i apologise and would appreciate a point in the direction of the relevant thread(s).

anyway, i have a 10kw woodburner and i'm burning dry wood and it is connected via a 150mm stainless flue pipe to a 180mm stainless flue liner. the chimney is on an external wall and the height is about 12 or 13m from the burner. i have fitted a flue damper just above the burner and it has helped quite a lot but i still don't get a lot of heat from it. If i get it burning well and then open the door i get a terrific blast of heat that lasts for maybe half an hour but then it dies down and i have to close the door and be cold for a while.

anybody tell me what is the problem? the woodburner itself maybe? or the flue too long? if so, what can i do about it?

 

[xr4x4]

What happens if you fill it with wood, open all the air vents and leave it for an hour?

 

[Agile]

There is a very big difference between the heat content of various types of wood.

A few months ago I posted a link on this forum which listed the typical heat output from different types.

My friend in France has a wood stove/boiler and that needs refilling every 40 min when its set to give a good output. I am not sure of the type of wood he uses but all I can say is that the trees are very tall indeed.

Tony

 

[ChrisR]

They burn a lot of Poplar in France. Always seems a travesty, it's decent furniture wood!

 

[Agile]

They dont look like English poplars, thicker and much taller.

He had a friend come to cut one down but it jumped at him and knocked him unconcious. Took fire brigade and ambulance to get him down bank. He made a full recovery and then committed suicide a few months ago!

Tony

 

[dcawkwell]

i have a coal fire place i left it burning well for 6 hours+ last week the room was still freezing get a nice gas fire

burning wood is just a backwards step

 

[igotalake]

fire running with all vents open for an hour it goes really well but not that hot. get it going well then close the damper and it's hotter. i almost never close the one and only air vent.

i have burned poplar (black hybrid), oak and acacia (black locust?) and there's not much difference except the poplar needs reloading more frequently.

 

[Norcon]

Does it have a boiler fitted?
What make?

 

[ALEC1]

that sounds like one hell of a flue for 10kws....its probably far too big, what do the manufacturers say.....also if a fire burns wood fast it needs replenishing pretty frequently....you do do that don't you....

 

[igotalake]

it's a Supra 'Mulhouse' with no boiler,

as to the flue being too big in diameter, the outlet on the stove is 150mm so that's the smallest flue it can be connected to. admittedly the majority of the length of flue is the flexible liner which is one size bigger.

 

[ALEC1]

what do the manufactuer's say?

 

[ALEC1]

http://www.supra.fr/medias/File/_doc_dyn/english/Foyers_export_2010.pdf

I found this...are the baffles in place?

 

[igotalake]

couldn't see mine on that doc but yes the baffle above the fire grate is in place, i don't think there are any others.

 

[ALEC1]

thats where i would be looking...why not get the manufacturer out?

 

[igotalake]

pretty sure the baffle above the fire box is the only one.

i probably should contact the manufacturer but i've got a feeling they will say go back to your dealer.

the flue damper made a lot of difference and also reconnecting the flue to the back of the burner with an extra bend rather than straight out the top made a good difference so this all leads me to think it's a flue problem i.e. too much draw.