Log Biomass Boiler System

A question about : Log Biomass Boiler System

Hi

There are several threads on here regarding Pellet Biomass systems but nothing much about Log Biomass. So, have any of you installed such a system? If so, can you give me a rough idea on your system size, amount of logs used, approx cost of installation etc? I have ball park prices for a boiler, thermal store and controls etc but wanted to get a feel for likely install/labour costs. Now the RHI is here I expect that it is a licence to print money!

Any reliability/performance issues? Good support from your supplier?

Any recommendations for Devon suppliers would be gratefully received.

Thanks

Best answers:

• I looked at installing a log biomass boiler this time last year. The cost of installation are about the same as for pellet boilers (Ј4k-Ј5k) which seems high for the hours of work involved. The installers I spoke to tried to dissuade me from a log boiler in favour of a pellet boiler. For some reason, they were saying that a log boiler only makes sense if you have your own supply of free wood. I disagree - briquettes are available around the same cost per tonne as pellets and anyone who has used a wood burning stove will have no problems lighting a log boiler once a day.
  When I researched this, I came upon a satisfaction survey that showed that owners of log burners had fewer problems and were more satisfied than owners of pellet boilers.
  The first golden rule of renewable heating seems to be choose your installer with care. Someone local, with good references is best because it's a 20 year relationship for servicing and maintenance. Lots of sob stories about non-local installers never returning to sort out problems. The second golden rule is get lots of references from the installer's customers - visit, look at the work, ask about reliability and quality, teething problems and snags. The third golden rule is, if the installer is good, take his advice on product choices. You don't want a situation where he turns round and says 'well if you'd gone for the one I recommended you wouldn't have this problem'.
  I couldn't find anyone local enough with good references so haven't invested in a wood boiler yet.
• Hi Robwiz
  Thanks for your reply. I've been researching a new boiler system for a few years and it makes sense to actually do it now due to the RHI payments. Will be glad to get rid of my ancient oil boiler!
  I have access to a small area of woodland so I should be ok for a few years. Looking at some case studies it does get a bit mind boggling when you see pictures of some of the log stores that people have. Still got to be a better deal than getting ripped of for oil every winter!
  I will be getting quotes sorted soon but, as an engineer, I have a 'need' to fully understand the technical side of things before I make any commitments! It annoys the hell out of my wife! I'm annoyed that I just don't have the experience with biomass or thermal stores and, therefore, I have to put my trust in a third party. Like you, I agree that decent support is going to be required which is why I'll be looking for a local company. There is a good company just down the road but I know their prices are going to be at the top end and beyond my budget.
  Anyone else installed this type of system?
  Thanks
• We got through 4 cubic metres of logs last year and that was just evening heating. You must have a lot of space to store logs.
• Well obviously it depends how much energy you require too. What kW rating is the boiler? Our stove is 12kW. How much space heating requirement do you have? You can use that to work out the amount of logs required (ish) in tonnes and then work out the volume (ish). See https://www.woodfuel.coop/logs-or-briquettes.html
  This is also a good chart to give you a rough idea of what you're paying per kWh: https://www.coedcymru.org.uk/firewood.html
  Also just found this, not sure how useful: https://www.dunsterheatltd.co.uk/newtowood.html
  On the subject of comparing cost with oil, I have found it's only when you purchase at a special rate that it becomes cheaper. For example, I purchase felled wood from a local tree surgeon at about 1/4 of the normal price of "seasoned" (yeah right) logs. Have to season it myself, but at least it gets properly dry. When you purchase from the local log man I'm pretty sure it's more expensive than oil (especially with oil at a lower price currently).
  Obviously if you have your own woodland that's cheaper still
• Thanks Smiley Dan.
  The first link is very interesting and does a good job in pushing briquettes, which is food for thought for when my wood supply runs out. I have a small copse to clear which I am hoping will take a few years to use up.
  I anticipate a system size somewhere between 40-60kWs as I have a 3 storey house so it will be a bit of guesswork as to the amount of wood needed. However, in my case, it will definitely be cheaper than oil as the old boiler used to burn through it like it was going out of fashion! If we had the heating on like most people would do then it would easily use 25 litres per day.
  I need to get a new EPC done to determine the current heating and water demand.
  Cheers
• From Spring 2015 if you want to use you own supply of wood you will have to register yourself on the 'biomass suppliers list' as a 'self-supplier'.
  See here for more information.
  However I would recommend pellet or chip boilers. As you can install a hopper and it can automatically feed the boiler as and when required and like oil or LPG you can have bulk deliveries 2-3 times a year and just forget about it.
  (also if you are going to self supply you can get your own chipper)
  Based on a 40-60kW boiler I would recommend looking at wood chip boiler, as this is much cheaper than pellets. The fuel delivery equipment is more expensive but it more than pays for it's self in fuel savings.
  In regards to installers, I would choose a boiler of your choice contact the UK distributors of that boiler and they will recommend you to a local installer.
  I would recommend ETA or Frolling boilers as they are the best on the market, so if you call Innosol or Spec Flue they will be able to advice you on a installer local to you.
  The installer is as important as the boiler you choose, because many boiler don't work because they are not fitted correctly.
  Also the heat demand on the EPC may vary from the heat demand indicated by the installer but remember it's the figure on the EPC that is used to calculate the RHI.
• Thanks captainhindsight, very useful information.
  I hadn't considered other biomass options as I have some trees to get through but you make a good point. The pending new rules for self supplier look like another layer of bureaucratic nonsense that might be best avoided.
  Regarding the the actual boiler, the 2 makes you mention are on my list of possibilities along with Treco's Guntamatic.
  A question on EPC's......I have read that the RHI domestic tariff is limited to 45kWh so does this mean that this is the largest boiler that can be fitted to be able to make a claim? If I fitted a 60kWh boiler could I not make a claim at all even though it is still a domestic system? If this is the case, why should you be penalised for needing a large heating system?
  Thanks
• The RHI is dependent on the amount of heat you need to heat your house and hot water, not on the size of the boiler.
  As they have to be installed by an MCS approved installer the boiler has to match the heat demand - you can't just bung a big one in and claim for it - it's the heat requirement as specified in the EPC.
  AFAIK you have to have the EPC/GDA done after the new heating system is installed - those more knowledgeable will be able to advise you better - otherwise have a good search round the Ofgem site.
• [QUOTE=matelodave;66608617]The RHI is dependent on the amount of heat you need to heat your house and hot water, not on the size of the boiler.
  As they have to be installed by an MCS approved installer the boiler has to match the heat demand - you can't just bung a big one in and claim for it - it's the heat requirement as specified in the EPC./QUOTE]
  I agree that the payments are based on the total demand listed in the EPC but I have read that the domestic tariff is limited to 45kWh boilers.
  I have used several calculators to work out each room's BTU value and then converted the total amount to kWhs. The calculators have given me values between 43 and 45kWhs. So, if a supplier slightly over specs my system (especially as I may want to heat my basement in the near future) and I install a 50 or 60 kWh boiler then would this still qualify? If not, then this seems strange to be penalised for having a large house to heat. Or can I still claim for the 45kWh amount?
  Thanks
• I've had a good look round the Ofgem site and can't find your 45kwh limit anywhere (that's not say it doesn't exist - but it's not mentioned). You might have to ask Ofgem yourself for clarification. Likewise I'm not sure if you can put in a bigger boiler than you need just in case you want to extend the building or heating system at a later date.
  I'm sure that the RHI has some limits otherwise there would be those who would try and claim it for a stately home - perhaps they can, but then it might not come under the rules for the domestic portion.
  Whilst looking I found a calculator which I tried out using the non EPC estimator and it's spot on for my situation (bungalow with air source heat pump). I've got a recent EPC and am receiving the RHI based on my heating & hot water demand
• Bit of a difficult one, to qualify for domestic RHI you have to use MCS approved boilers and installers.
  However MCS only certifies up to 45kW, (commercial installs and RHI don't require MCS) so in short you need to fit two boilers.
  Say you need 60kW, you will have to install two 30kW boilers which are commissioned and installed as a single install/heating system and then claim the domestic RHI.
• So to clarify, it's not the amount of heat you need that's the limiting factor but the size of boiler.
  So multiple boilers (presumably from the approved list) can be installed to supply the required heat demand?
• Biomass boilers can be worth their weight in gold, because with them you can get RHI which means any unused energy can be fed into the grid, and you get paid for that energy too - so it's really handy stuff. Plus the fuel costs are a lot less than your average gas bill too so if you can get one, you should go for it.
  I guess it's hard to know where to turn though when you're after one of these things - after all there are plenty of firms but how do you know which one to use ? For me I just got some quotes in and did some googling too that's how I ended up with stl heating. I mean there may be some firms near you, but do get some prices in first.
• Generally it's better to choose a larger capacity boiler for logs or wood chip because it's most efficient to burn hard and get the heat energy into the thermal store. There's a case to be made for installing a 40 kW boiler when the heat demand is 24 kW because it will need loading and running less often.
  If you have a 45 kW boiler you might need to burn several batches on the coldest days, but much depends on the size of your thermal store. A good installer will be able to advise and lay out options.
• I would agree with that for logs, but I would disagree for wood chip boilers.
  Wood chip boilers have just as much control and functuality as wood pellet boilers so there is no need to burn in bulk to get the highest efficiencies or convenience
• Also for log biomass and the rhi , the Walltherm boiler is going through the motions with mcs atm is a great product now but would be even better if it qualified for Rhi
  https://www.walltherm.ca/