Multifuel stove and combi boiler

colbs

Hi guys,can anybody please advise me if it is possible to run a multifuel stove with back boiler on an existing combi boiler central heating system?.Ive read through a few archives but am confused by Neautralisers,heat exchangers and heat sinks???.I can gather that this is not a straightforward rig but just confused with it all.I have a 12kw stove with 34000 btu boiler? that i'd hoped could be rigged up to run at least some rads or better still hot water aswel. Thanks in advance for any advice offered.

Canucklehead

Hi

The combi system will be a sealed system under pressure.
I don't know what you mean by multi fuel , but these would generally be open vented systems. The two won't mix .
The stove can do rads and hot water, but then you lose the mains pressure of the combi for hot water.unless you have an unvented cylinder which will cost you at least £500 just for the cylinder. You need a G3 qualified installer for it.
Maybe if you get a good understanding of terminology it will become easier to work out what you want.

Corgi Guy

gksperth

colbs wrote: »

Hi guys,can anybody please advise me if it is possible to run a multifuel stove with back boiler on an existing combi boiler central heating system?.Ive read through a few archives but am confused by Neautralisers,heat exchangers and heat sinks???.I can gather that this is not a straightforward rig but just confused with it all.I have a 12kw stove with 34000 btu boiler? that i'd hoped could be rigged up to run at least some rads or better still hot water aswel. Thanks in advance for any advice offered.

I have been investigating all this for two days online and have now just plum,ped to get the central heating guys and the stove installer to meet at the house next week and put their heads together
From what I can gather so far to run the combi boiler for SOME RADIATORS and maybe the water and the stove for either different radiators R the water no problem ..
to have the stove heating the water u must also have a hot water tank !! and this has to be able to be gravity fed }

the central heating people I have been speaking to and the stove people generally dont ever really do the combi C.H boilers and stoves together though it seems as stoves to heat the radiators are mostly needed by people with huge OIL bills in areas where they can't get mains gas so not many would be brave enough to investigate it all

I think the neutraliser thing is something that will make the boiler take over from the stove for the water !! or maybe vice versa} when water is hot enough.
na din the summer when u dont have the stove on the boiler would then heat the water

I hope to have the Ch in next week and am now more likely just to get a simple stove for heating the room and not worry about gettin one to heat the water too ...
now that I think about it all more it still baffles me

will see what happens on monday and try to come back here again with news :-]

at least it is all easier than the registration thing for the forums ...
I must have put the wrong verifiaction code in ten times to register as wasn't sure what was a capital and what was small case letters :-]

Cardew

It is strange that a similar subject has come up twice today - having never come up before as far as I am aware.

http://forums.moneysavingexpert.com/showthread.html?t=716447

This is what I wrote:

Whilst it is possible to get this done - a combination of log burner and gas boiler both feeding into a Radiator CH system, I would strongly advise against it.
I have a similar system, with a Baxi open fire and a conventional gas CH system, that was installed when I had this house built. Had I known the complications, I would have just had gas CH and a normal open fire(without connection to the CH system)

Without getting into the detail, if you have a multi fuel system heating a water CH system there are important safety considerations to be considered. The water can boil and boiling water in a closed system is a potential explosion, so you have to have quite elaborate safety systems in the event there is a power failure.

My gas CH system(into which the solid fuel system water feeds) is not a combi. However the difficulties I faced will still be the same.

The big pitfall of my combination of systems is that the fully pumped HW and CH water also feeds back to the Baxi fire even in summer when obviously the fire is not lit; so I have an unwanted warm ‘radiator’(the water jacket of the fire)

Now obviously it would be easy to fit a valve to stop this. However this is extremely dangerous. If the fire was ever lit with this valve closed(someone forgot) you will have an explosion as the water will boil in a closed loop. Thus no Corgi fitter would dare fit such a valve.

The other complication is that you have to have a separate thermostat and an electrical circuit to sense the hot water from fire to turn on the CH pump.

Be interested in what your plumbers say.

janebucks

There is a way. See here: 'H2 Control System' http://www.h2panel.co.uk/h2index.htm

Cardew

janebucks wrote: »

There is a way. See here: 'H2 Control System' http://www.h2panel.co.uk/h2index.htm

Welcome to the forum.

There are a number of ways that the 2 systems can be combined, and my system has also worked for years; it is not too disimilar to that shown in your link.

The point being that it is complicated and expensive(by the look of that system).

Personally I wish I hadn't bothered; but then my open fire is in a reception room that isn't used a great deal.

honeywell_2

colbs wrote: »

Hi guys,can anybody please advise me if it is possible to run a multifuel stove with back boiler on an existing combi boiler central heating system?.Ive read through a few archives but am confused by Neautralisers,heat exchangers and heat sinks???.I can gather that this is not a straightforward rig but just confused with it all.I have a 12kw stove with 34000 btu boiler? that i'd hoped could be rigged up to run at least some rads or better still hot water aswel. Thanks in advance for any advice offered.

Certainly possible, as mentioned before check out the Heating Innovations website, as a new user I'm not allowed to post links but you can find combi boiler and solid fuel boiler linked with the H2 control system layout in the H2 panel layouts section.
Would advise that you phone 01354 653854 and speak to their technical bod Mike Smith, have worked with him before and I think you will stuggle to find anyone in the country more knowledgable on the subject of linking boilers. The H2 panel is in my opinion technically and practically an excellent piece of kit that does the job, and yes you could say I have an indirect interest but still my opinion for what it's worth.

Rolandtheroadie

I priced it up as well. Cost was going to be £3100 for the work and I still had to buy my boiler (about another £1400).
That was to combine oil central heating with a multifuel stove via a dunsley neutraliser. £400 was for replumbing downstairs so your talking 4100 all in.
I believe the problem comes from one system backfeeding another system (why the neutralisers needed).

Our solution is a stand alone multiburner in the livingroom. It's an 8.5kw and should keep us warm with the oil only used to heat upstairs before bed and first thing in the morning.
Cost so far approx £400 for the fire, £200 for the flue liner, £200 for a hearth and work (inc opening up the chimney a bit more) flue pipes, registry plate, bird guard etc about £150 too.
Hoping flue gets dropped tomorrow (dont know costs yet, hoping approx £100) then I'll do the rest myself.

We've got a local place for beech seasoned firewood ready to go for £50 per ton.

mikes334

I found a great place for chimney liners and fireplaces at ChimneyLinerDepot.com. They had the lowest prices around.

honeywell_2

scotsman4th wrote: »

I priced it up as well. Cost was going to be £3100 for the work and I still had to buy my boiler (about another £1400).
That was to combine oil central heating with a multifuel stove via a dunsley neutraliser. £400 was for replumbing downstairs so your talking 4100 all in.
I believe the problem comes from one system backfeeding another system (why the neutralisers needed)..

Would expect that buying and installing H2 panel instead of system based around a dunsley neutraliser could save you a good deal of cash. You must consider that the H2 is a complete system, when you unpack a neutraliser that is when your problems start, you must design your system (or preferably pay a heating engineer to do it for you) decide on how many addition pumps, motorized valves etc you will need to fit, all very costly.

Alternatively, buy a H2 panel (around 500-600 + vat), bolt it to the wall, usually in your airing cupboard, run pipes from oil/gas boiler and solid fuel boiler to the panel, connect returns, cylinder and radiator flows. Fit cylinder and solid fuel pipe stats (supplied with panel) and wire these along with programmer, boiler etc to the standard 10 terminal box fitted on the panel, all internal wiring to ensure the motorised valve open and close at the correct time and in sequence is already done.

Once fitted everything operates automatically, a friend installed an H2 18 years ago and he has never touched it since, he's thrilled with it.

andymacuk2001

Hi

We're just about to move into a new house with a an baxi back boiler and 1960s style gas fire. We're not yet sure how much space there is in the fireplace so any thoughts are currently very embyronic. However, I want to know if it's likely to be possible to replace the g rated back boiler with a a condensing back boiler, but with a wood or multifuel burning stove instead of a gas fire.

Id like to keep the existing open system because it allows for the connection of solar thermal when we can afford it, and also we won't have to undergo as much replumbing as we would with installing a condensing combi boiler somewhere.

Is it possible to install a woodburning fire in front of a new gas back boiler?

Thanks

Andy