I can confirm the above as this has happened to me in our master bedroom.Last year we had fitted a cast iron wood burner the bedroom is rather large and I rather like the flickering flames at night.The black pipe goes through the wall and then straight up to fix against the outside wall at the top is the spinning cowl.From almost the outset the problem big-wheels has noted started just outside where the bend goes vertical to above roof level black tar started to leak down the wall even though the burner did not get excessive use. This year we have been getting lots of smoke inside the room so I replaced the cowl which had tarred up and was a little worn, Still have problems in that the fire will burn until I close the door then the flames are extinguished. What I did do whilst cleaning inside the fire box was to disturb the baffle plate and it came off its 4 pegs that hold it in place in the roof of the fire box. Now I am not sure which way round it goes. Tomorrow I will drain rod the whole pipe for any blockage. I think I will have to start from scratch and replace the whole pipe but can anyone help re the correct fitting of the cast iron plate inside the fire, I think its use is something to do with burning off the secondary gases but it appears at the moment to be close to the roof of the fire box above the chimney stack but leaving a gap of a couple of inches for the smoke to escape,Can this be right.

I strong recommend reading about the dangers of carbon monoxide.

er, its a smokeless wood burner

the plate comes of for cleaning or it knocks of easy.you can see witch way it goes by the way it sits on the pegs.yes it sits very close to the roof .take it off again and look to check the adjustable butterfly behind the plate.make sure it opens by the handle.(like its not just the hande on its own moving)or you may have a birds nest in the flue.or is the enough air getting in for the flames.have you emptyed the ash pan.that all I can think of.Im not a fireman.good luck

Sure but if it has no ventilation or not enough........ HERE

I've had Hunter which at the time I thought was brilliant cos it had a back boiler then we moved to a house with a Franco-Belge & I'd never buy another make again - controls were simplicity itself'; an almost dead-looking fire (or so OH thought) could be lit up like turning a switch simply by opening one of the only two controls. I did find UK supplier websites, but didn't trawl hard enough to find how I could obtain in Spain.

Yes it is a baffle plate that sits just below the stove pipe inside the stove.

May I thank you all for your replies. This fire does not have a butter fly damper Betris We have a large log burner in the sitting room , I can almost get inside it, We used so much wood I have now put a grate inside to cut down the amount used as it was getting too hot. The glass door alone is 44 inches long X 22 inches deep. Half way up the chimney inside the house is a damper or butter fly The fire which is giving the problems does not have a damper the glass on that fire is only 10inches x 12 inches Cast Iron. Just got my rods so whilst its sunny I'm going on the roof for a poke down the chimney. I will replace all the pipes to the double skinned as per info above but it can wait until the summer.

Hi all just to say thankyou for all your responses, I neglected to express my thanks earlier. We are in the process of seeking out a suitable stove and intend as adviced to have the chimney run through the upper floor and out through the roof (well if all goes to plan). Hopefully this will provide some heat to the upper floor and save a little on the electricity costs for heating (currently using oil filled rads). We shall not be embarking on the fitting ourselves as we would not want to risk life and limb.

When we lived in Sayalonga we had a wood burning stove and found that the glass door got very dark brown - solved it by cleaning it with oven cleaner every now and again.
I can now taste the jacket potatoes we used to cook in there - delicious.

Can't speak for how toxic they are, but there are loads of cleaning compounds in Spain specifically for the glass of woodburners. And they're very good

We use one of the many cleaners available at local supermarkets for the glass, but its also possible to clean it with scrunched up newspaper dipped in the ash from the fire, which will bring it straight off.

Yes, that's what we do - very effective.

Or a scotchpad pan scrubber and a bit of water.

I can understand the ash, very old system. But doesn't a pan scrubber scratch the glass?