Logburner Advice

[Alex]

For the past 4 years we have had 2 multi fuel stoves in our cottage which I mainly burn sold fuel on but this afternoon I thought I would just burn logs on the one in the diningroom. I took grill thing (technical term) out of the bottom of it as I have been told that wood burns better on a bed of ash and lit it the same way as I would if I had been using coal. All was well for 20 minutes but now, 2 hours and one log later, the room is cold and the glass on the door is still so cold that I can comfortably put my hand on it. Where am I going wrong please ?
The stove has vents above and below the glass doors, should I have these open or closed ?

Thankyou Alex

 

[Flyfisher]

Weve just had a multifuel stove installed in the bedroom we use as a 'bedsit' while awaiting the heating system being installed in the rest of the house. It burns coal and wood equally well using the 'grille thing' (I'm equally at home with these technical terms :wink: ) and the instruction booklet doesn't suggest removing anything when burning wood. When burning wood, the ash does build up on the grille but it takes a little while. I find that burning a couple of loads of wood quite fast builds up a decent layer of ash and quickly gets the stove nice and hot, after which I close it down a little bit. Our stove has an 'optimum' setting which seems to work very well.

Our model has air controls at the top and bottom of the stove and, apparently, wood burns better with airflow from the top so when burning wood I close down the bottom vent. When burning coal, the bottom vent needs to be open. But all that might depends on the stove design. Do you still have the stove instructions? If not, I'd suggest replacing the grille and having another go. Besides, with the grille in place, you can then alternate wood and coal as required.

 

[Zebra]

Mine only burns wood, it doesn't have the grille thing (glad we're all talking the same language here) and some days I have to try four times to light it. It depends on the wind direction, the temperature of the air in the flue, the dampness of the wood, lots of things.
What I do is individually scrunch up eight to ten sheets of newspaper, put some kindling on top, and one small log, light it, shut the door with all vents open, maximum air flow. I wait until it's got a bit of a glow - some heat in there - a bit of a heart, then load it up full with logs, shut the door again, wait a bit for it to get hot again, then shut the vents down so that a minimal amount of air goes through, and then it burns slowly for hours.
Or goes out.
On mine, the vents at the top of the doors are the airwash ones - if you let the air in there, then the air passes over the doors on its way to the heart of the fire, and this keeps the doors clean. The vents on the bottom of the door let the air straight into the heart of the fire. I also have a damper on the rear of the fire, which restricts the amount of air that can leave the fire and go up the flue, and it's mainly this which I use to control the fire. Too open, and it burns too fast and all the heat goes up the flue; too closed, and it doesn't get enough air to burn well, or lets smoke into the room.
Two hours and one log doesn't sound like enough to me. Once I've got mine going, I shove about four logs in there, and they'll last about an hour before it's ready for some more.

 

[Flyfisher]

OK, I'll come clean. Firelighters.

Light two of those individually-wrapped firelighters (better than the large packets as there is no wrapping to open and so no smell to escape) in the stove, throw in a handlful of kindling (I use a mixture of twigs and small branches) and a couple of smallish logs. Shut the door and open the airvent to get a good 'boost'. Never fails.

 

[Alex]

I should have known that the technical terms would not be lost on here :wink:

Flyfisher - Instructions :? not something that came with our stove, that will teach us for buying 2 stoves from a well known internet auction site. Its actually going quite well now and giving off heat but then I did light it at 2 o'clock this afternoon. I also have to admit that I didn't put anymore logs in for a couple of hours (sorry Zebra) but I now know for tomorrow. You both seem to do the same thing when lighting your stoves so I will try doing exactly as you have both suggested and then try with the 'grille thing' in the next day and see which works best for me.

It seemed silly and a complete waste of money buying so much coal as we have a garage that has been half full of logs for the last 3 years and a neighbour gave me 6 ash trees that he cut down and cut into 8 foot lengths, ready to be cut up and stored until they are seasoned.

Thank you both for your advice,

Alex

Flyfisher that was sneaky ! I did use firelighters, I was just too ashamed to mention them in the original post.

 

[DJH]

Hmm...a firelighter , some kindling (dry as possible) a few lumps/knobs of coal to give a bed of hot embers and then DRY well seasoned split logs and enough air to let the logs burn brightly which will keep the glass clean on its own.

The instructions with one of our stoves said that for burning logs the primary air should be as closed as possible (without starving the fire) and the secondary (airwash) control half open. It doesn't mention anywhere about removing the basket or grill for coal or timber...

I forgot to mention you need a big basket of logs by the fire so you don't have to go outside in the cold and dark to fetch more...

Doug

 

[Flyfisher]

Alex - perhaps you could find the instructions on the manufacturers website? Though my bet is that if you replace the grille thing all will be well.

Doug - those settings are exactly as described for our stove (Stovax Stockton 5). I reckon they'd be a good starting point for Alex's stove as well.

You're right about having a large basket of logs sufficient for the whole evening - though an emergency bucket of coal is a handy standby to avoid a late night and chilly errand for more logs.

 

[Alex]

Thank you DJH, I am definetly going to try it tomorrow with the grille thing in. I am also pleased to report that the stove burning logs is now throwing out more heat than the stove burning coal.

Must get another log basket.

Alex

 

[chuckey]

I believe that wood has 20% of the heat energy as coal per kilo. So if you burn 20 KGs of coal a day to get the same heat you have to burn 100 KGs of wood or a log every 15 minutes. I have got both both a multi fuel burner and a wood stove. We only use coal in the multi fuel because otherwise you spend your life fiddling about with wood. Also the wood burner is very sensitive to some thing, one minute it flares up with flames going up the chimney, so I turn down the air adjuster and the bl***y thing goes out :evil: The coal on the multi fuel burns evenly all day long, topped up in the morning and evening. shame it rots through the flue liner in two years. :?
Frank

 

[Alex]

I am ashamed to say that after a week of trying to just burn logs......................................... I have failed
I have tried with the grille thing in but after 20 minutes the logs just smoulder for 2 hours no matter what I do. I will keep trying though as I have so much free wood. The good news is that I am thinking about a job with South Wales Fire Service as I seem to be an expert at putting fires out.

Alex (Fireman Sam)

 

[88v8]

Two stoves.

Our Clearview is easy to light, twelve balls of newspaper, some kindling arranged in a criss-cross, mix of gleanings and pine, perhaps a fir cone or two in the beginning of the year when the flue is cold, once it's alight gradually start to close the dampers, put a light log on then another, gradually closing the dampers, watching the thermometer, eventually the main damper all the way closed just running on the airwash which also pretty well closed. Very controllable. Up to temperature in about three minutes from cold, then one can start with heavier/denser logs.
Only burning seasoned dry wood, although it will light with damp unseasoned stuff.
The grate has the bars set quite close, readily makes and maintains an ash bed.
Can leave it half an hour between twiddlings, although the temp does drift down.

Moisture meter to check the wood, should be 30% or better.
Thermometer on the flue pipe to monitor the temp, don't get it too hot or it will burn the liner, nor too cold or it deposits tar in the flue.
I never burn coal.

Our Esse is pretty much useless unless the wood is dry. Sulks, takes half an hour to get going, tries to go out. We're using kiln-dried, expensive but heyho.
The bars were too wide apart. Ash fell through. I bolted a steel plate onto the bars covering most of them, left a strip 1" wide and about 12" across at the back (it's 15" wide), the rest of the firebed is just flat plate, so now it makes an ash bed.
Light it much the same way, except nine balls of paper as it's smaller. Up to temp in four/five minutes. The dampers are crude, pretty well closed or open, and with the damper and the airwash fully shut it still burns rather fast. Basically it's just not a very good stove.
At 5kw nominal it uses probably more fuel than our 9kw Clearview.
In windy weather it's hard to light and burns much tool fast, but that's a problem of the chimney rather than the stove, too much draft. Really it needs a flue damper.

Not all stoves are created equal.

Nor are all chimneys. A good installer will check the draft with a gauge, not just shove the stove in, take your money and run.

Old stoves become leaky. The body may distort especially if it's been run too hot, at the least the door seals may need replacing every few years. If air can get in just anywhere then the controls are defeated and it will burn too fast.
On a calm day, with no fire, put a smoke grenade in there, close the controls and see where smoke comes out. Ideally nowhere. Better still if you can put a bag over the terminal to block the flue outlet but even without doing that the smoke leakage should be apparent. Best done in the evening when the room is dark and you can show up the smoke with a torch.
Remove batteries from smoke alarm

Ivor

 

[Greg.Hobson]

Hi Alex.

2 stoves, 3-storey stone house, 250metres up in the pennines, burn only wood and aim to have the same gas bills summer and winter.

As 88v8 says, not all stoves or chimneys are equal. Our 2 stoves are like chalk and cheese, as are the chimneys. 88v8 also talked about a flue thermometer - a must-have bit of kit that is also cheap!

Also a must-have is a flue damper - a butterfly valve in the flue about 12" above the stove outlet. Again, a must-have and cheap bit of kit that is easily fitted by oneself.

Bone dry wood is also a must, particularly for starting the fires. I burn almost 100% off-cuts from furniture makers or joiners, all kiln-dried and then stored in their workshops and under cover at my house. I burn c.300cu. ft. wood per winter - a closely stacked pile 10footx6footx5foot.

A trick I learnt for the smaller (5kw) stove (which sounds similar to yours), is to arrange the wood in pairs of roughly equal size to create a square or rectangular hollow pyramid, decreasing in size to the top, effectively creating a vortex up through the middle, concentrating the heat onto the baffle plate, thus heating the space above it, maximising the effect in the stove. This will achieve 300 degrees C on the flue thermometer in about 15 minutes from lighting. From this point onwards, I can do pretty much whatever I want with it.

Not mentioned so far is how smaller pieces burn far faster and hotter than any split log (unless it has no side greater than 1" wide). The burn efficiency is noticeably affected by the size, and in particular the ratio of surface area to volume, of the wood used. A high ratio will burn hotter/quicker than low. It seems obvious, but the effect is quite dramatic.

I always mix small pieces with larger pieces throughout the burns (mainly because my supply is largely small pieces) and often have the difficulty of stopping the stoves (both/either) from going thermonuclear, particularly in this windy weather and the consequent effect on the draw of the chimneys.

I also remove the flue and clean it out myself (it just lifts off and out) about every 2 or 3 weeks, depending on how good my burning technique has been. (I maintain a special vacuum cleaner just for this). This definitely needs doing if the maximum achievable flue temp drops below about 200 degrees.

It has taken me the best part of 10 years learning to get to this point where I can heat our 175-year old, ex-barn sufficiently (that means cheaply) for me and my wife (the kids have a differing opinion!).

I hope this helps.

 

[Zebra]

Ivor and Greg, both those above posts are very useful. Having had a woodburner for three years and never bothered with a flue thermometer, I've just ordered one on the strength of your comments.
I do hope everyone's managing to keep the rain out of their homes this evening. Having lived with holes in the roof and wet walls, and now being nice and dry, I send best wishes and tarpaulins to those still struggling.

 

[middi]

Some really interesting points as to how to keep a wood fire working efficiently,
The thing that really amazes me though, is how the heck the stone age people ever managed it without the science :wink:

Middi
( ps. Merry Xmas to all on PPUK )

 

[Keith Bowman]

And no-one has yet mentioned the science of what sort of logs: read, mark, learn and inwardly digest!.....http://thankstrees.tripod.com/id16.html
And a cheery beech log fire for you all this Christmas

 

[Greg.Hobson]

Hi again.

On reading my post I realise I made an error on the positioning of the flue-damper. It should be quite close to the stove - just above a radius of the flue up from where the flue joins the stove, so about 4" for a 6" flue. It is the thermometer that goes 8 to 12 inches up from the stove.

Middi. The stacking trick I learnt on a holiday on a game reserve in South Africa. The nice ladies came and lit the braai (barbeque) by stacking 3" logs in this manner and just lighting a bit of kindling in the middle - the effect was amazing! Mind you, 35degree daytime temperatures helped with drying the wood! Wood is the staple cooking fuel amongst the locals so obviously they get a lot more practice than we do and the impact of it not working would be more severe.

When I used to work, a common saying from the top was "Stolen from the best with pride."

 

[CliffordPope]

As I keep endlessly repeating to my family when they fail to get fires to burn, the secret is in the preparation.
You need a good stock of dry graded wood of different sections - kindling through to big logs, and the aim is always to have a good roaring flame. Feed in larger wood as it takles hold, and never let it get to an insipid smouldering state by neglecting to top up in time, or putting on wood that is too big.

I agree with the use of top-air. It feels counter-intuitive, but experimenting confirms that logs like it better.

 

[DJH]

Has anyone got one of these? They're cheaper on e-bay...about £50 or so... 8)

http://www.irelandstoves.ie/index.php?route=product/category&path=40

Ho ho... :lol:

 

[MatthewC]

The stacking trick I learnt on a holiday on a game reserve in South Africa. The nice ladies came and lit the braai (barbeque) by stacking 3" logs in this manner and just lighting a bit of kindling in the middle - the effect was amazing! Mind you, 35degree daytime temperatures helped with drying the wood! Wood is the staple cooking fuel amongst the locals so obviously they get a lot more practice than we do and the impact of it not working would be more severe.

I saw a similar sort of skill in Uganda: somehow the local women could keep a fire burning using three long bits of split eucalyptus arranged like a three-bladed aeroplane propeller with the fire at the hub, slowly moving each piece of wood into the centre as required. This was a standard practice for cooking outdoors; even wood is precious there!

 

[Lime]

I was a boy scout and have no problem lighting a fire. I can do it almost anywhere.
In the house, the key thing to remember is that wood needs a bed of ashes to sit on directly to burn properly.