Retrofit wood-fired hot water into new, oil-fired CH and HW system?

[NorfolkBumpkin]

Hi all,

I'm feeling rather sheepish as I should have done my homework weeks ago, as you shall see, but I am where I am...!

We've recently bought a new house and spent the past few months renovating it, which has included a new Charnwood Cove 2 wood burner and new oil boiler, hot water tank and hot water/CH system (with expansion cylinders rather than a cold water tank in the loft). The plumber we used (who we have no problems with and have used many times before) told me that fitting a woodburner-backboiler into the system would add substantial extra cost and so, disappointingly, we decided against.

However, I've been thinking that I should have got a second opinion and that is what I am doing now. I'd be grateful if anyone can give me an idea of the feasibility and (very) approximate cost of installing a backboiler onto the Charnwood (you can get a flueboiler to fit our stove which I guess is the sort of thing we'd be looking at) and using this heat to complement the indirect hot water system which is currently heated by the oil boiler (and immersion).

Any comments gratefully received - please bear in mind that I'm not a plumber so my technical knowledge is limited.

Thanks,
Alex

 

[SimonG]

Is it an unvented hot water cylinder you have? reading your post it sounds like it.

 

[Gray0689]

I agree sounds like unvented
You can't have an uncontrolled heat source incorporated with unvented cylinders
Only way you can do it and have mains pressure water is by a thermal store

 

[tamz]

As everything is unvented it is now a bit of a problem. Solid fuel needs to be connected to vented systems for obvious reasons.

There are a couple of ways to do it but none are particularly cheap or easy to do now.

 

[ecowarm]

It sound like you have left it too late now Mr Bumpkin, it would be a bigger and more expensive job and defo not DIY

 

[quality]

You can have an unvented cylinder heated by your wood burner but you would need an open vented heating system as ecowarm has suggested it will not be cheap to do it Properly

 

[SimonG]

That'll be the H2 panel then? I noticed on their website they have a version for unvented.

 

[NorfolkBumpkin]

Many thanks for all of your comments - I may have just to leave it then and carry on forking out on oil! Thanks for your help.

 

[Solid Fuel]

Hi
Had an oil fired unvented system feeding a vented dual coil hot water cylinder & sealed radiator system.
Fitted a Charnwood insert solid fuel boiler feeding it via the spare cylinder coil, tee'd from feed before coil into pump and into existing unvented radiator run (unventing it). Check valves after each pump & standard PSV's in place.
Happy with performance ran both to max no issues.

 

[Gray0689]

Hi
Had an oil fired unvented system feeding a vented dual coil hot water cylinder & sealed radiator system.
Fitted a Charnwood insert solid fuel boiler feeding it via the spare cylinder coil, tee'd from feed before coil into pump and into existing unvented radiator run (unventing it). Check valves after each pump & standard PSV's in place.
Happy with performance ran both to max no issues.

This don't make sense to me???