Wood burners, big or small?

[crossy67]

Looking at buying a wood burner to take with us early next year. We have central heating but don't really want to use it much if we can help so were thinking wood burner in the living room and thick socks for the rest of the house.  I was thinking get a big wood burner and leave all the downstairs doors open to allow the heat to take the chill off the rest of the house.  I was wondering if there are any disadvantages to having a big burner if we wanted to shut the doors and just have it ticking over, are they very inefficient or would we struggle to get it to burn right with a small amount of fuel in.  We are looking at round the 16-18kw mark.

Thanks folks.

[:)]

[Quillan]

The only thing I would say having watch my mates cutting 50cm logs in half for their little wood burners and considering that most wood is normally sold in 50cm lengths just make sure your fire can take them.

[Théière]

woodburners running on tick over will tar up the chimney much quicker than the right size fire running at a good burn. Our logs are delivered in 1m lengths so two cuts and we have 3 logs for burning.

[Clair]

We use our Jotul F600 wood-burner as our main source of heating.

It has been on 24/7 for the last 6 weeks. I stoke it up and turn it right down before going to bed and restart it in the morning from the ambers, with no ill-effect on the flue (I know as Mr Clair does the ramonage himself).

We have an electric radiator/towel-rail in the downstairs bathroom and it is set at minimum to prevent any risk of frozen pipes, but it has not yet come on. It's is on just in case...

Our upstairs rooms are very well insulated and not heated , save for a 2m² area of underfloor heating in the bathroom. There are no doors separating the upstairs and downstairs and no doors in the upstairs area either (except to the bathroom) and the minimum temperature there has been 12°C so far, at night, when there is no heat coming up from downstairs.

This works well for us, but, as I mention above, there is a shed-load of insulation under the roof and against the north-facing back walls. Also, the wood burner is centrally positioned in the house, so the heat can circulate quite well almost everywhere. Once the interior is warm, the thick stone walls help retain whatever interior temperature is attained and it stays warm, provided the wood burner is fed.

Next door in the gite, there is no heating upstairs either and very, very poor insulation. Once the rooms get cold, they stay cold all winter, no matter how much wood we may burn in the insert (one of the main reasons I don't rent out in winter). The thick stone walls help retain whatever interior temperature is attained, currently 8°C.

[crossy67]

Thanks for the info.

So using it on low mainly with the odd blast at full chat to warm the place up should be ok then.  [;-)]

[mint]

I'm not joining in (sic!) cos I'm done with woodburners.  Can no longer put up with the ash and dust they spew up.  But, if they light your fire, as it were, Good Luck!

[joidevie]

On the question of "ramonage" (cleaning), am I right in understanding that it needs doing once a year (twice if 7+ stere are burned p/a) and can be DIY? (I believe a pro chimney sweep is really hard to find due to the vast insurance costs)? And that for house insurance you are required to keep the receipts for the purchase of the brush kits from the brico shop? (I suspect there may be many unused 'kits' lying around in people's lofts & cellars..).

Cheers..

[sid]

I'll join the "big or small debate" to add my two-penneth to the chimney sweeping question.

We went for a larger woodburner than our room actually needs (according to the chauffagiste who fitted it we only need a 4 or 5kw model). He said that we would be running the fire at a low setting and that consequently the chimney would get much dirtier than it should. Teapot has already pointed this out, and that is what happens.

I find that I need to clean the chimney at least 3 times during the winter. There is a build up of tar, which I think if left will constitute a fire hazard. This tar (also known as creosote) burns fiercely. I've seen some horrendous photos of the deposits which can look like black volcanic lava and eventually this will block the chimney! Our chimney liner tends to get a build up of black shiny granular deposits. By sweeping every 6 or 8 weeks I'm able to remove this. I'm not really sure whether it is absolutely necessary, but I'd rather be safe than sorry. The job takes about a hour including cleaning up afterwards! 

The other option for us was to have a small woodburner installed, but the disadvantages are that they generally only take small logs and cannot be kept burning overnight. So, we went for a 9kw model with "feu continu" facility. What we find is that we have the lounge door left open and the surplus hear can circulate through the downstairs rooms.

There seems to be a lot of contradicting advice about chimney sweeping but I gather that it is no longer a legal requirement, as many people will claim. It is very simple to do the job yourself and I find that the best solution is to have the chimney swept professionally once a year and do any necessary cleaning yourslef during the wood burning season.

 

[joidevie]

Interesting thoughts.. We just had a Jotul 18 (an old one from the 1980's) insert fitted (18kw) which is quite over powered, but we hope to heat much of the downstairs with it.

Our 'fumiste' or 'chauffagiste' has told us about the 'requirements' of cleaning (but like you say, there seems to be different 'views' - I may just ask at my AXA insurance for their position) but he has also said we should clean the pipes (flexi type) from on top of the roof downwards? As it's pretty high, I was wondering if this is in fact the case?

And do we have any more 'knowledge' on the legal requirements on cleaning?

Cheers..

[Théière]

Not being a lawyer cannot comment on the legal position but the insurance used by Credit Agricole via information from Britline said must be swept every two years but did not have to be done via a ramoneur.

[sid]

I don't have any more legal information concerning how often the chimney must be swept, sorry.

Sweeping can be done from the top, but I would find that daunting with the height, slippery roof tiles etc etc. I find it easy enough to do from the fireplace. If you have steel liners you should use the nylon-type brush head.

You say you have "flexi" pipes? I don't know what is permitted but I thought that for a woodburner the liner needed to be steel (stainless usually) and not the flexible type normally used for oil boilers. However, I stand to be corrected on this side issue.

It's also important to burn only dry wood, oak or ash, as damp wood causes condensate problem, and resinous softwood causes more tar deposits.

That's just about the total of what I've learned about woodburners, and most of it is on this forum already.

 

[crossy67]

Great info all even if not strictly relative much appreciated any way.

Thanks a lot.

[mint]

Crossy, there's a big shop on the river in Chalais where she has some models on display and she even has a sale now and again.  If you can source your own installer, all the better as you don't really want to be roped (conned) into using her chappie.

Also, I saw some on promo at our local Leclerc but I don't know if the promo extends to other branches of Leclerc.

[crossy67]

Thanks Sweet, we are coming over 6th next month to (literally) sign our old lives away so I could wander over there to take a look.  I have seen a few round here for between £4-600, how does this compare with her prices?  Oh, and can flue liners be joined if I bought two long lengths?

[mint]

We bought the Godin Carvin which was then about the largest they made, 13 KW.  I think we paid about 1700 euros but for the fitting?!  In the region of 6000 euros to fit that and the large Godin oven that we bought at the same time (least said the better about THAT job).  It's probably worth visiting the shop as it's so near you and she has been a supplier for some years so does know her stuff.  She's very helpful and, as it's her own business, she'll look after you OK.

As I have said, just ask about installation costs BEFORE you proceed and, even then, proceed with extreme caution.

If Aubeterre is going to be your principal home, please ensure that you understand the conditions you need to fulfil to enable you to claim tax credit on the appliance.

[crossy67]

Yes we will be living in Aubeterre from early next year (scary as hell).  To be honest, at 1700 Euros we would probably be better getting one we have seen here and not bothering with the tax rebate.  I really hate not to support local businesses being, one my self, but we are on a budget the savings are huge.  Still, I will take a look whilst I am there signing for the house.  6k for installation, didn't you already have a chimney or did they have to build it for you lol.

[mint]

Crossy, I did say the least said about the costs of that job, the better, didn't I?[:D]

Anyway, all the best for the 6th.  It's been very cold here (don't know whether better or worse than Wrexham) so make sure you have some really warm clothing with you, especially if you then have to get the woodburner going before you could keep warm![;-)]

 

[Rob Roy]

Crossy67 you don't say in your OP anything about how well your house is insulated or what it's constructed of, which can make a difference to the efficiency of your stove. We have found that once the old stone houses are heated through they retain the heat well, but only if you have really good insulation. We have a Franco Belge that is bigger than we really need and it does exactly as you are hoping, if you leave the doors open the heat drifts around the house. If we have the doors shut and the fire dampers turned right down it still works really well and when stocked up with wood for the night will still be alight in the morning.

[crossy67]

I am trying not to think too much about the insulation yet, there is none as far as I am aware.  It is a 3 story stone town house with a big cellar.  I do intend to insulate the roof but it's going to be difficult as the top story bedroom ceilings are nailed onto the roof trusses.  I don't expect the whole house to be piping hot, just the living room and to stop icicles in the others.

[woolybanana]

Insulate under the floors first as the cold will come up from those cellars too

[crossy67]

That's the easiest and 1st bit I am going to do.

[BIG MAC]

When you say insulate the cellars have you thought that out fully? We are converting our cave into our winter snug and putting a woodburner in it. If you think about it...pipes which are far enough underground....don't freeze. Ground source heating is well known. We intend to insulate to promote stability of temperature in the cave but are more concerned with insualting upper floors and replacing windows to keep the heat that travels up in the building. In an ideal world I would love to have a PV array - immersion element and a back boiler both charging a thermal store from which heating would run...maybe one day when I have €10,000 spare I may think about it again....

[crossy67]

I was going to do it more to stop draughts, we have lived in a house with suspended wooden floors and on windy days the carpet used to levitate.  The cats found it a bit scary lol.

[Théière]

[quote user="BIG MAC"]

When you say insulate the cellars have you thought that out fully? We are converting our cave into our winter snug and putting a woodburner in it. If you think about it...pipes which are far enough underground....don't freeze. Ground source heating is well known. We intend to insulate to promote stability of temperature in the cave but are more concerned with insualting upper floors [/quote]

Whilst pipes under sufficient ground don't freeze, they certainly don't stay at a temperature that would support human life. Obviously depending on the stone the cave is constructed from will have some effect but being surrounded on all sides by damp earth will mean uninsulated all the precious heat will be lost in no time. Ground source heating works because a large area of heat pipes feeds a small area of living space and that has to be very well insulated.

[joidevie]

[quote user="sid"]

You say you have "flexi" pipes? I don't know what is permitted but I thought that for a woodburner the liner needed to be steel (stainless usually) and not the flexible type normally used for oil boilers. However, I stand to be corrected on this side issue.

[/quote]

It seems it is allowed and quite common though only the most heat resistant tubage is recommended..

People talk of 'hedgehogging' their pipes every couple of years ..