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Thinking of a wood boiler. Am I mad?
 Started by  simBad
 24 Jan 2009, 7:39 PM

My old oil boiler has just about had it and I'm considering one of these new high efficiency log or pellet boilers. i have access it a source of wood but I would really appreciate some/any feedback from people who are already using them.
Two concerns really:
1. How much wood am I going to need?
2. How controllable are they and should I consider installing one if I am out at work quite a lot?
Obviously my concern stems from the oil crisis of late last year but although things have calmed down a lot wood appeals to me as the right local type choice but would it be a rod for my back?
I will try to answer both questions at once:
The average UK home will need about 11 tonnes of wood per year for all it's heating needs but like any heating system there will be many variables such as the efficiency of the boiler chosen, the location you put it in, how airtight and well insulated your home is and how you burn the wood fuel.
A wood pellet boiler may be your best choice if you are away from home for a large number of hours each day because these are the most automated. However log boilers can be installed with accumulator tanks so that a single burn can be carried out each day which, if designed (sized carefully) will provide 24 hours or more of heated water for circulation around the heating system of the home.
Find out who your nearest supplier is and ask them if they can offer refs of homes where similar systems have been installed where the homeowner may be happy for you to visit or have a chat on the phone. many wood boiler users are happy to talk about their experiences.
bruce davis (Guest)
I use a wood boiler in Vermont,U.S.A where it is much colder than England and I like it very much.Logs should be split and dried for one year under cover.To gauge how much wood you need you would can estimate at 160 gallonsof oil per cord. Remember that solid wood burning in a wood boiler makes much more creosote than a wood stove.I brush my chimney (the boiler is in the house) once a month which is mandatory for fire safety.
I am thinking of installing a wood burning esse, I have a friend with a multi fuel Rayburn and he keeps his running 24 hours a day on wood and anthracite. I do not know how much wood he uses but I think he uses about 3 tons of anthracite. Bear in mind we both live in the north of Scotland in the Glenshee area which is always cold in the winter so depending on where you live you may not need to burn it for as long. His wife is at home most of the day as is my wife so easy to keep an eye on a wood burning boiler, the pellet option may be better if you are out of the house. The Rayburn ashpan has to emptied every day which i think is a bit of a chore.
I am new to the wood burning scene and have spoke to someone about thermorossi boilers. They seem quite reasonable but have not heard of them ,anybody know anything? I am coverting a church so it will have to be around 50kw
I have heard of them Graeme but don't know anything about them. i have a 50kW Baxi and am happy with that. My usual advice is try to find one that sucks the combustion air in from behind the firebox rather than on that blows it in from the door or the front.
I'm a newbee here and am a little daunted posting a comment (with the level of knowledge displayed by previous posters), but,a brand that I think has been over looked generally in the UK market is Prity (its Bulgarian, but you guys probably already know this, dumb newbee) They have an excellent range of multifuel boilers. Graeme was looking at around 50KW, they have a compatiable boiler. Also some one earlier on the tread mentioned, stoves with boiler, plus top ovens. You guessed they do them as well. Sorry if you all know this,but I'm feeling my way.
Hey whichburner, don't you have a website selling Prity stoves?
jsheldon (Guest)
Hello All,
I'm new to the forum, but have done a bit of research on the question of how to heat the house we're restoring in Hastings, UK. We're trying to decide between an Austrian wood boiler (which, unlike the one mentioned by the Vermonter, burns wood efficiently enough to keep the creosote to a minimum) and an eastern European masonry heater/boiler, which has the advantage of lacking computers and moving parts.
On 25 Jan 2009, 5:58 PM GBP-Keith said: "The average UK home will need about 11 tonnes of wood per year for all it's heating needs..."
I'm surprised at the amount of wood you postulate as necessary. Is that figure based on the use of a standard wood stove?
mike7 (Guest)
jsheldon - This site may help:-
having planted a 4 acre forest a few years ago, i'm now considering installing a wood chip boiler in a new well insulated house. we are finding it difficult to source a boiler that is not industrial or under 25kw and needs a large silo / storage room.
anyone had good experiences with wood chip ? any suppliers or products recommended ?
or should i go for a pellet system ?
" I'm surprised at the amount of wood you postulate as necessary. Is that figure based on the use of a standard wood stove?"
It is based on the average UK home and with a woodburning appliance as the only source of heat. Obviously a house built to passivhaus or similar energy standards would require just a fraction of this.
Advice to dinger. I would avoid woodchip and look for a pellet or log system.
dinger (Guest)
thanks keith. but why would you suggest not to use a wood chip boiler ? i have not heard anything against them. having said that i have not seen one in a house yet !
i am told that pellets may go up in price even as much as the price of oil
wood chips seem to be more available and i can chip my dried timber
i am told that i can also use pellets in the wood chip, although not getting the max output
Wood chips can be very difficult to get and keep dry. they also very easily block up in the equipment especially if you change supplier. (chip sizes vary as does the material that chips are chipped from.
Tommy (Guest)
We had a wood boiler, but the problem was that by the end of the winter we were up to our necks in ash. Unless you have a country estate, what do you do with the amount of ash that they produce? There is only so much that a garden can take and if you leave it for the dustman to cart away to landfill sites, it's not very 'green' either.
dinger (Guest)
i have 4 acres of woodland which i can place the ash around the trees
you say 'had'... so what did you replace the wood boiler with ?
any other negative things about it ?
is the new system better now ?
i was going to chip the wood myself so that the chips were all the same size
GBP-Keith (Guest)
Still difficult to keep dry dinger. You will need to turn them regularly so a bobcat or similar would be needed. Without this action the chips will start to compost.
thanks guys for the advice.
it seems unless you are going for a huge wood chip boiler for an industrial or business setting that they do not really work for small residential set ups. too much work and potentially too many problems !
so i have decided to go with a 20kw pellet boiler, plus extra solar panels heating a 1500l buffer tank. i may add a log burner and connect to the buffer using the timber from the site that i had intended to chip.
do you think this is better way to go in an airtight, well insulated new house ?
thank you.
A 20kW boiler is a huge thing. How high is your demand?
It is usually cheaper to reduce the demand then to increase the energy supply.
From 2010/2011 onwards the CO2 output of powerplants will be taxed per tonne, co-firing with bio fuels is the answer of the electricity generators. Expect an x-folded price for pellets. Resources are limited. And the small consumer buying on short notice will pay the biggest bill, having the smallest influence on the timber market.
You appear to be replying to everybody, mostly in a very condescending manner. I have been looking thru a lot of the subjects, but have not yet found one started by yourself, or have you.
Good for you
Some people dry the waste strips of wood (with bark on) from timber production and then chip them.
Here in Yorkshire we have access to hard and soft wood which we cut up, split if required, and store. Our UK manufactured convection stove just heats the air and is a 5kW clean burning model (smokeless zone quality). Our house is 40 years old, brick and breeze block two storey detached with good insulation and has a floor area of about 50 sq m. Most of our windows are East or West facing so not much solar gain in the winter.
Last winter we burnt the wood stored in a volume of approximately 2.6 cubic m. and used our gas boiler very little for space heating. We were surprised how having the stove on all day on a really cold day(below freezing) would warm up the house; the thermal mass of the house keeping it warm (not hot) until the next day.
It is easy to fit too large a stove which should not then be run at a low output, as this does not maintain a high enough stove pipe/ chimney temperature and get good combustion. We found that on cold days we would light the stove in the morning for a few hours and then have a second long firing after lunch. On cool days we would have the stove on for say 3 hours from meal time to early evening. On a cold damp summer day we may fire up the stove for an hour in the evening, burning soft wood.
Our old inefficient gas boiler has a gas input heat to the heat exchanger of approx. 15 kW and will heat up a cold house and do the hot water, but it is never on all the time to keep it warm even on the coldest of days. Heat input to radiators etc. is probably less than 10 kW with about 0.5 kW into the kitchen from the boiler casing.
Ash (from timber) is not a legal fertiliser, using it as a fertiliser is illegal. We live in the EU and have to stick with existing waste laws.
Esp. Scandinavian timber ash can be so high in radioactive matter (the outfall from Tchernobyl) that the timber itself (unburned) is already illegal to be traded.
Some realy have the pink glases mixed up with the green view....Blue eyes + pink glasses=green vision (smiley)
ALL timber ash is to be treated according to EU waste legislation as WASTE, not to be used as fertiliser unless the batch is certified by the national agricultural Department.And no such certification has been issued in the EU so far..... This is due to the content of heavy metals in timber which are concentrated some hundred times in the residue.Standard knowledge of any gardener.
Here the relevant legislation concerning fertilizers:
Note that Sweden, Finland and Austria have stricter legislations concerning the content of cadmium. Others can eat the rubbish, what the heck....
heinbloed.Regrading the area of Swedish forests that were affected by fallout from Tjernobyl it was only about 2.6% of the total forest area, and concentrated in one particular area, around Gävle
We know,fridihem, other parts of Sweden had simply 'adjusted' the max. permittable Bequerels.
Aren't there still huge amounts of forest fruit deepfrozen, kept until the day of judgement on taxpayer's cost?
The Swedish timber industry/society weren't the only ones who got their forrests radiated, it hapened all over Europe.But there is no control what happens to the 'manure' of the Atomic Mafia, see this link:
Aparently radioactive timberfuel is traded all over the world, pure chance that someone private found a small batch, some thousand tonnes in Italy.

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