Central heating system with two heat sources?

Ok folks here’s one to test you. We currently have an oil fired combi boiler, heating hot water and radiators, we also have an open fire in the lounge where a solid fuel central heating stove once was.
We want to install a woodburning stove with a boiler/waterjacket and re-connect to the central heating system in place of the open fire and intergrate the two heating systems so that the two boilers can be run separately or in tandem.
Can it be done, are there different methods, are there any acknowledged experts in this field, does anyone have any experience and are there definite do’s and don’ts?

Defiantly possible. Possible method below perhaps?

If the oil system is open vented (don’t know if you can get unvented oil systems) I think you can do it easily and directly by more or less plumbing the woodburner into the primary system. If not I think you would have to go down the route of a thermal store with the unvented system on a coil and the vented system on the main thermal store fluid / primary system. Not an expert plumber just bits I’ve picked up on a few systems.

Going through the same thoughts at the moment. There are 2 basic ways of doing it.

1. Combining the heat sources and using the existing CH and HW circuits. For this you need a Neutralizer or a fancier version of it.

Neutraliser – http://www.dunsleyheat.co.uk/neutralizerpics.htm or
H2 Panel http://www.h2panel.co.uk/h2index.htm

2. Using a thermal store to power the HW and CH. This would involve a new tank, but maybe the more efficient way of doing it.

http://www.newarkcoppercylinder.co.uk/cylinders/solar_thermal_store/

This also allows you to plumb a solar feed in.

Decisions, decisions!

thermal store would be my first port of call. Also alows you to add solar thermal very easily.

plenty of issues.. cost must not be one as it will.. if you just use the stove as a heat only source for the ch would be the easiest but.. you ll have to find some way of running the pump in the boiler or by passing it with a seperate pump for when the stove is on you could do this by zoning off both appliances you have to have a store somehwere for the stoves heat and again that would need zoning off generating DHW from the stove though would be vastly more complex and impracticable in my opinion.
my professional opinion would be keep the stove seperate. for the money you ll spend and potential issues with mananging a quite sophisticated syatem you ll never save money.

I’ve done it using a Dunsley Neutralizer … don’t be fooled it’s just a metal junction box, nothing fancy in there at all, no valves, no baffles, no nothing. Dunsley are also a little slow at helping out with advice, etc.

It’s quite a complicated job, you may find it hard to convince a plumber / heating engineer to look at it.

Good luck.

It’s a combi boiler, just run the main flow and return through the back boiler for the simplest solution. Then when the boiler is running, the stove will heat the rads but not fire the burner as it won’t be required.

Other way really would be to treat it as a separate system, far more complicated and expensive involving a new pump, relays, zone valve, stat etc etc

You’re not going to be able to use it for hot water production anyway, so forget that one unless you want to fit a tank and rum the combi as a system boiler

Esse do one too.

http://www.esse.com/pdfs/Centraliser.pdf

As do Stovax

The Esse version is around £300 or so IIRC

Fm .. sounds nice but how will the water circulate as the pump in the boiler will be off.. and i’d run the mother of all magnetec/ fernox sytems to keep the crud out of the combi.. and the stove will be a massive heat sink if its not lit but the boiler is.. not looking for negatives but finding plenty

indeed you are quite correct, however I did say simplest.

That’s how I run mine and to be honest it works quite well overall. I just leave the timer/stat set on the boiler permenantly a usual and when the stove is lit, the boiler doesn’t fire up. Its only a 7kw stove so dont really notice much heatsinking.

Have a magnaclean duo fitted anyhow on the return.

The stove is right at the end of the main of the flow/return, not ideal but it was the easiest place to do it. Thermostatic valves fitted everywhere except the bathroom, which is locked open

Thanks to all, great to have different peoples thoughts on it, lots of usefull information and links to further sources. Hive intelligence is wonderful.