wood burning stove/back boiler

[jocelyn plummer]

Would be glad to hear from anybody who uses a cast iron wood burning stove connected to a back boiler for domestic hot water and radiators! Efficiency/cost and reliability/ would be helpful!
Thanks in advance!

 

[Flyfisher]

We've just had a complete new system installed using a multi fuel boiler stove (stovax Stockton 11HB) and a gas boiler linked into a single heat store that provides the heat for DHW and radiators, including underfloor heating.

It's a bit early to give any real information about efficiency, costs or reliability but it's going to be an interesting winter of learning!

One thing we are currently trying to figure out is how to 'tune' the system so that all the heat from the boiler stove goes into the heat store instead of into the 'heat leak' radiators, which have to be installed and capable of sinking enough heat from the boiler stove in the event of a power failure stopping all the CH pumps from working.

Also, the big win for us is that we have plenty of free wood to burn. If you have to buy wood then stoves are not particularly cost effective compared to a gas boiler, even though they may be far more comforting.

 

[Greg.Hobson]

Also, the big win for us is that we have plenty of free wood to burn. If you have to buy wood then stoves are not particularly cost effective compared to a gas boiler, even though they may be far more comforting.

Depends on the price you pay! For the last 5 years I have aimed for £1/cubic foot delivered and am somewhere near that target, but it is a challenge. Once you have found a good supplier, it is a godsend.

FYI, we get through around 300 cubic foot per winter and this years supply will cost around £350 to £400. We burn joinery shop off-cuts. Beautifully dry birch, sycamore, beech and some ash. The sizes can be variable but it does all burn.

 

[skier-hughes]

For the last 5 years we've had a wood burner/back boiler connected to a 1000l heat store, coupled with solar tubes for summer hot water and rayburn for when that is on and giving off heat as well in the winter.

Reliability, brilliant.
Cost, well we get lots of free wood, offcuts from a shed manufacturer and a fence manufacturer which we use as kindling, and lots of trees to cut down for burning away.

Ours is a 40kw fire, it gobbles wood, but then we are at home nearly everyday, all day. When you are sat at a desk working at a pc, then you get a little cold mid winter....(well Jo's cold now) so the fire goes on all day long. The solar tubes have been fantastic, normally gibing us hot water from May to September. We ran out of hot water during washing up after the party, but we had 10 house guests and 4 in tents to shower etc and 120 bowls, plates sets of cutlery and umpteen glasses to wash up, so it's not surprising that we did run out.

Having the heat store means if we heat up the water of an evening, we can have the central heating on in the morning before the fire is lit. Which is nice

I think in maybe 15 years when I'm getting on a bit I won't be able to chop enough wood, so we'd have to start buying it. It'll be costly.

I reckon we'll burn a builders bag of logs in 2/3 days when it's really cold. Our house is quite large to heat.

As for efficiency, burning logs hot and fast is supposed to be the most efficient way fo doing it, so having a heat store means you can do this.

It takes a few weeks/months to get used to how to burn, when to burn logs etc, in particular when your heat store is reaching 75'!!

Ours has a mains cold feed which is activated if it all gets too hot. We've activated it twice!! In the early days and it works a treat!!

 

[a twig]

We have a huge woodburner with back boiler, that runs 4 radiators (kitchen, living room, dining room and conservatory) via an electrickery pump. Needless to say I shall be removing the conservatory one in short order

How well it works depends entirely on the quality of the wood. Some well seasoned oak or ash and we are in our shirtsleeves and the wood lasts a nice long time. Lesser wood or poorly seasoned, and we get through a huge volume of timber to get the same effect.

That being said, our woodburner is also an old one, with leaky rope seals and poorly fitting glass, which doesn't help its efficiency one bit! y parents have a similar set up, which is very frugal with any kind of timber and runs more radiators.

So, a takeaway of key points from our perspective:
1) Make sure your wood burner is in good nick and appropriately sized. Too big, and you plough through timber for no reason, too small and you'll never be warm enough!
3) I would avoid one with glass windows, the best performing ones I have seen have been solid iron with no glass.
4) Make sure all your pipe runs etc are insulated and as short as possible to minimise transit losses.

 

[jocelyn plummer]

Thank you everybody--you have confirmed my thoughts---brilliant and cost effective if you have your own supply of logs being one; work involved as one reaches ones dotage the next, and worse still sitting in a room and feeling the temperature drop as the embers cool -------and of the course, I should imagine that the ultimate insult would be to run a bath or shower and find either no hot water or it getting gradually colder because somebody has forgotten to keep the fuel up. :roll:

Presumably it's one of those things that work well for some once used to it but not something to take on after living with just a 'flick of a switch'.

 

[Flyfisher]

That's a fair summary of the dilemma.

I only had a gas boiler linked into our system on the insistence of Mrs FF on the basis that she would be unable to cut down our trees, log them and then split them using the tractor then carry two wheelbarrow loads into the house each day, just for a bit of warmth in her dotage ( probably on the basis that I,ll work myself to an early grave with all this lumberjacking :lol: ).

A possible compromise is to get a multi fuel stove and burn coal instead of wood. On a per kW basis, there's not a lot of price difference if you're buying wood by the load at commercial rates and there's less to carry around and it burns for longer so requires less frequent refuellings.

Of course, your 'green' friends will condemn you as the spawn of Satan for even handling the black stuff, so that's a decision only you can make.

 

[agbagb]

I can't add to this as ours heats the house via air circulation (or not if the doors are shut).

But - I heard recently that wood burners with back boilers in domestic homes now qualify for a feed in tariff !!! . So the prospect might now be a little more interesting.

 

[Woody3]

Ours is a 40kw fire, it gobbles wood, but then we are at home nearly everyday, all day.

Can I ask what make & model your stove is please? We are installing a very similar set up, but haven't decided on a stove yet...

 

[Flyfisher]

I can't add to this as ours heats the house via air circulation (or not if the doors are shut).

But - I heard recently that wood burners with back boilers in domestic homes now qualify for a feed in tariff !!! . So the prospect might now be a little more interesting.

A little more interesting perhaps, though If this information is anything to go by . . .
https://www.gov.uk/government/news/the-heat-is-on-for-householders
. . . I suspect the requirement to meet insulation requirements might work against the average period property, and £200 per year is hardly likely to change lives, though it may be a way of encouraging people to spend many thousands to help boost the economy ( cynical? moi? :wink: ).

 

[skier-hughes]

Ours is a 40kw fire, it gobbles wood, but then we are at home nearly everyday, all day.

Can I ask what make & model your stove is please? We are installing a very similar set up, but haven't decided on a stove yet...

LECHMA, it's a polish brand. Our fitters were Polish, have been living in Scotland for many years, but use the technology they were brought up with living in a cold climate where wood burners etc have been used much more.
I'm sure they had an English site, but I can't find it. Google translate works well enough to understand it though.
http://www.lechma.com.pl/kominki-z-plaszczem-wodnym/wklad-kominkowy-wodny-standard-prosty-32kw-uo-detale.html

We also have 17 radiators, some 9' in length, so there's a lot of hot water needed to heated.

 

[88v8]

Presumably it's one of those things that work well for some once used to it but not something to take on after living with just a 'flick of a switch'.

Went from gas heating, to storage rads + woodburner, now + two woodburners, one of which I'm reinstalling with a barometric damper.

We buy most of our wood. 2 metres of seasoned, most beech + a bit of birch, was £190 cut and delivered although I still had to chop it into thinness.
We already had about a metre, that in total will probably get us through the winter. Heating only, evenings only, no water other than what my wife saves in thermoses from the two kettles that live permanently on top of the stove.

The 3cum of wood - say three tons - has to be chopped and stacked then carried up to the house then stacked in the fireplace then burned then the ashes removed. A far cry from gas central heating, a fraction of the heat at a gazillion time the effort.
And woe betide you if you run out of wood after Xmas - seasoned wood by then, like hen's teeth.

Ivor

 

[jocelyn plummer]

Gosh--I reckon all that huffing, puffing, chopping and stacking, to say nothing of keeping hot water aside in flasks, is definitely enough to put me off--OH has to watch his back too. So, if I view a cottage that has a back boiler wood burner I need to find out how much it will cost to convert the whole system by installing a state of the art electric combi --- no gas mains, and we all know about oil. arrgggh

 

[discobarry]

We are also looking at the possibility of a back boiler stove but after some thinking it looks likely that we will soon have an induction range cooker with a stand by side log burning stove. We have two other stoves in the house a 7kw which heats the living room and some of upstairs and 4kw which is in the bedroom. When we get the kitchen stove we will have suffice heat from wood/coal, and at the moment i have a 4.8m by 2m log store full of wood with 1/3 of it being seasoned. Some of the wood is ours but we by off a local tree surgeon at approx £90 for 2 cubic metres which is pretty cheap, all i have to do it stack it.

Do what you feel is best, look at all your options and costings and try finding a good supplier of wood. Wether you prefer joinery offcuts which will be a lot cheaper or sometimes free to paying for good looking seasoned hardwood is your choice but it's much nicer than having to pay a fortune out in lpg gas at £600 a pop.