Wood burner central heating system?? Advice needed.

[LongEarsShortLegs]

Hi there, moving into abother house asap that needs renovating and will be installing a wood burner in the kitchen/ diner ( since they'll be a sofa in the room and I'll spend most of my time in there). Number of reasons for this

1) I like woodburners, friends have them and it's just a nice thing to have in the room

2) I have a fairly large supply of free wood, so can potentially save some money on bills.

3) I'm a man, therefore I like fire!!

Originally was going to bung a 5/6kw stove in the room, job done. But have recently been thinking about having a wet stove... current plan is looking like this:

8-9kw stove.
1 gravity fed towel radiator in the upstairs bathroom
1 central hearing pump controlled by 2 pipe stats, powering 2/3 rads ( 1 In the living room, 1 in main bedroom and possibly one in second bedrooom)

House currently has a semi modern fully working GCH system and would rather not go through the upheaval/ cost of integrating the system unless theres a major reason too.

Anyone see any issues with my idea/ plan?? Is already cold mains in the loft, so would need a small metal header tank in there.

Reason I'm thinking of doing it this way is obviously the rest of the house ( save the hall/ landing/ study/ downstairs wc, box room- none of which we would spend much time in ) is getting heat from a free source. The other rooms would require running of extra pipework/more rads( with some of these rooms not really having space for 2 rads) and obviously a bigger stove and more wood to heat rooms we don't need to heat.

Having found a stove or 2 I like in the 1200-1400 range, £400 on flues etc, any reason why I couldn't have this done for sub £3k??

Also regarding building control if I chose to use HETAS registered engineer for the stove could I use a regular plumber to plumb in abd sign off the additional rads rather than doing it all myself?

Advice/ criticism/ being told it's a disaster is all more than welcomed.

 

[Roger928]

A wet stove needs quite a bit more fuelling. And to run them efficiently you have to run them as hot as possible.
Though heating a cylinder is an added bonus.

If you've no vented cylinder then a dry stove would probably be a better option.
Open plan contemporary stoves are all the rage now. In new builds the chimney starts at the first floor with a steel girder doing the heavy support work.

 

[sbgasman]

you really want as many of your rads as possible running off gravity in case the pump fails,you should also have a heat dump,get yourself a good hetas guy that does the wet side as well.

 

[LongEarsShortLegs]

you really want as many of your rads as possible running off gravity in case the pump fails,you should also have a heat dump,get yourself a good hetas guy that does the wet side as well.

I had thought this myself and could potentially run 3/ 4 rads off gravity with a vent into the header tank. However it means a lot of unsightly and expensive big bore copper pipe into rooms.

So would ideally only have 2 gravity fed Withe)the vent going to the header tank ( as could literally run straight up and down with the feed and return, with rads going off this pipe at either side to 2 upstairs rooms.

Then on the other 2 ports ( or using an injector tee if a 2 port boiler) have a pumped system running smaller bore pipe into the room next door and to another bedroom.

Only reason for wanting to do this as opposed to a dry stove is I reckon over a winter I currently go through £3-400 of gas to heat the house. Whilst the house is gutted the extra cost of a bigger wet stove,4 rads, some copper pipe ( even at £6-7/m for 28mm) , 2 pipe stats and a c/h pump is fairly small. Which I think I could get back rather quickly and then be eating into the actual cost of the stove/flue etc

Whereas with a dry stove i think the savings will be minimal as the other half will still want a warm bathroom/bedroom do will have the c/h running for that.

 

[sbgasman]

On mine at home I have a rayburn royal range cooker,I have 3 large cast iron rads all running on gravity and have never had overheating problems,I also have a manual dump valve,rads are one in our bedroom one in grandkids bedroom and one in bathroom,we have 2 back to backs knocked into one,so have lots of different levels, so the heat from the stove rises up through the rooms if you leave the doors open,I think you may be surprised how much heat you get from the stove itself, you would really be best to get say 3 pros round to give you some quotes/ideas,much easier when you can see the job.

 

[Agile]

Many people successfully combine a stove output with a gas boiler.

I don't see any good reason for you not to do that.

As long as you are prepared to do the cutting and refilling the stove. I would find that very tedious. My friend in France has a stove supplying about seven rads and I found it would take me about 25 minutes with an electric chainsaw cutting and that amount of wood would hardly cover an evening's needs. It also needed refilling every hour or less.

Tony

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• Agile
• 1 May 2013
• 2

 

[muggles]

It can be done, but your budget of £3k is too small for a decent installation. You need to carefully consider the output to room/output to water ratio as well as boiler output ratings - if 70% of the heat is coming into the room then that room is going to have to be either very big or hotter than Hell in order for you to get a sensible amount of heat into your radiators in the other rooms.

WoodWarm and some of the Charnwood range are good makes to consider. What have you been looking at up to now?

 

[LongEarsShortLegs]

Many people successfully combine a stove output with a gas boiler.

I don't see any good reason for you not to do that.

As long as you are prepared to do the cutting and refilling the stove. I would find that very tedious. My friend in France has a stove supplying about seven rads and I found it would take me about 25 minutes with an electric chainsaw cutting and that amount of wood would hardly cover an evening's needs. It also needed refilling every hour or less.

Tony

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• Agile
• 1 May 2013
• 2

2 reasons for not wanting to combine it

1) cost, speaking to a plumber I know about my plans and he was basically saying the pipe/rads/stats needed for a wet system are basically £500 then a day or 2 to fit.

On the other hand with a condensing combi boiler with no hot water tank and a pressurised heating loop im going to be looking at a lot more complex and expensive set up with a thermal store, heat exchanger, changeover valves etc, but I'd still need the gravity fed rads in the system anyway. - he may be talking *******s but he's the 1 mate I know who's a plumber and till I get the keys I can't do a lot with regards professional quotes/ ideas

2) as you say wood demands/storage. Running a wood burner and 3 rads will use roughly double the wood of a dry stove- which is doable. However running 9 rads ( if I turn the ones off in the wood burner heated rooms) and hot water I'm looking at 5x the wood of a dry stove, meaning my whole garage/ garden would be a giant wood store.

 

[muggles]

As long as you are prepared to do the cutting and refilling the stove. I would find that very tedious. My friend in France has a stove supplying about seven rads and I found it would take me about 25 minutes with an electric chainsaw cutting and that amount of wood would hardly cover an evening's needs. It also needed refilling every hour or less.

Tony

If it's burning that much wood it's either very inefficient or badly specced (or you need a new chainsaw chain). A modern Charnwood boiler stove needs refuelling about every four hours

 

[LongEarsShortLegs]

It can be done, but your budget of £3k is too small for a decent installation. You need to carefully consider the output to room/output to water ratio as well as boiler output ratings - if 70% of the heat is coming into the room then that room is going to have to be either very big or hotter than Hell in order for you to get a sensible amount of heat into your radiators in the other rooms.

WoodWarm and some of the Charnwood range are good makes to consider. What have you been looking at up to now?

Been looking at charnwoods ( possibly with the boiler flue)

Also been looking at a trianco Newton 8kw boiler stove ( purely as I know someone's who's got a none boiler stove off them and it seems to work well)

Mendips are another I've been browsing

Aga Minsterley is an option, as although bigger than what i was originally looked at has been mentioned in passing that I might be able to get money off aga stoves via a friend who works for theme.

 

[Agile]

I still think that combining a stove with your heating system would be a good thing to do. That's without having a hot water cylinder.

But your friend seems to be thinking big money for a stand alone system.

But if you want to save money, my thought is that you should combine with the existing so that the heat goes where you need it without needing to fill the house with additional rads. But saving money means a lot of wood cutting and storing! You don't get something for nothing even if the wood if free.

The stove I pictured above was quite good for the purpose although I don't know the make or model.

It replaced one with clever temperature controls but it gave about 6 kW into the room and very little into the water.

The pictured one puts most of the heat into the water and very little into the room. As there are two rads in the room that's fine. It seems to put about 6-7 kW into the water and hardly 2 kW into the room. Only manual controls on the firing rate though.

Tony

 

[LongEarsShortLegs]

I still think that combining a stove with your heating system would be a good thing to do. That's without having a hot water cylinder.

But your friend seems to be thinking big money for a stand alone system.

But if you want to save money, my thought is that you should combine with the existing so that the heat goes where you need it without needing to fill the house with additional rads.

Tony

Am i/my plumber friend missing a trick to do with integrating as the way hes explained it to me is I would need a large thermal store in the loft, some sizeable changes to the already installed pipework and would still need gravity fed rads.

He was basically saying I could get a gravity fed and pumped 3 rad system for £1000 on top of stove price if he was too come into the house with no making good and floorboards etc already lifted. But if combining it with the central heating system it would be more like £4000 ( but with a lot more floorboards lifted and a lot more to tidy up afterwards.



I just Googled ( I have read up on the theory before) fitting wood burner to combi and the first link is this:

http://www.stovefittersmanual.co.uk/articles/fitting-a-stove-to-a-combi/

Which I hadn't read but basically suggests the option I was already on about above ( and the picture of vertical radiators has suddenly made me think I could possibly get away with a totally gravity fed system).

 

[muggles]

Is your plumber HETAS Registered? He needs to have his HETAS wet installations ticket if he's going to be working on or installing a heating system connected to a stove

 

[Agile]

A thermal store is a way to get hot water heated by your stove. Good when wanted but expensive. You don't seem to want that as you already have your combi for that.

What I suggest IF you want a wet fire is to have a simple connection to your existing heating system so the spare heat from stove can heat your existing rads. You will still need a gravity rad and suitable header tank though.

 

[LongEarsShortLegs]

My plumber isn't Hetas hence asking whether I could get a regular plumber to sign off the wet side. As I can't I will either go the building control option ( since I need to have them in anyway) or HETAS for the lot.

My plumber was saying ( possibly wrongly) that I'd need a thermal store or an expensive heat exchange unit as I can't mix the pressurised heating system with a an open vented wet stove system so would basically need some way of passing heat from one to the other.