An Interesting conundrum for a professional plumber....

[ukkid76]

Hi all, I am new here, although my plumbing knowledge is pretty good, I've fitted many central heating systems in properties I own or have bought and sold, everyone has been overseen and signed off by a registered plumber so all above board,

My question “I think” is quite interesting,

I live near Naples in Italy, (most of the time) I have a smallish property with a combi boiler central heating system,
I bought a second hand wood burning stove and two new large radiators in the UK and brought it down here,

I will do a water and pressure test on the wood burning stove and won't attempt to install it until I am satisfied with that test,

What I want to do is install the wood burning stove in the corner of my downstairs area, we have one large room,
Then run the flow and return pipes “24mm or thereabouts” up the wall and across the ceiling, then through the ceiling straight into one large radiator “600x1.8 double convector”
The flow and return pipes would be at least 8 meters long,
I will then run a single pipe “20mm” up into the attic and install an expansion tank with pressure relief valve and automatic air relief valve, I'll stop off the part of the valve which the water inlet connects to.

I will tee off from the new radiator to the existing heating system which has all been done in 10mm piping, “so 24mm straight into 10mm”
As this is already connected to the combi boiler I can re-fill the system from the combi boiler end or the system,
I will also install a Grundfos circulating pump close to the wood burning stove wired via a heat activated switch so when the wood burner is lit and the water warms up it'll start the pump automatically and hopefully circulate through the house,
And the wood burning stove will/should warm up the downstairs.
Am I stupid or will it work?
I am more interested in the heat from the wood burning stove but thought if I could use the heated water as well it’ll be a bonus......
I don’t have or want a water tank as the combi works really well with the shower and hot water outlets, and I would love to fit a solar heating tank on the roof for free hot water throughout the summer months,
If all of above is a bad idea is there any way I can use the wood burning stove without filling it with water i.e. filling the water jacket with sand or something?
Thank you in anticipation......
Dave Cox

 

[AWheating]

it all depends on the regs in the country and whats allowed, it would not be allowed in the uk really as a wood burning stove normally has to be fitted to an open vented gravity system because there is no safe way to control the heat source. I would suggest you need to speak to a local engineer in italy about whats possible.

 

[tamz]

Do what you like. You are far enough away from me so i'll not hear the bang or even read about it in the paper.
Reconsider your thinking for the sake of your family and maybe get a bit local professional help.

 

[Howsie]

Sound advice!

 

[WHPES]

Am I stupid or will it work?

Without meaning to appear rude, what you suggest is extremely dangerous and most probably illegal in your country. Pipework diameter too small and whatever country you are in it needs an open vented system and heat leak radiator at least. Two systems must be separate or through a purpose made unit and you can't link a combi.

Get a professional for the sake of everyone's safety.

 

[Billy Bob Bob]

good advice from tamz and whpes,you would be advised to take it

 

[DirksPlumbing]

I am afraid I could only repeat what has been written above. The system will work until the big bang. Please do yourself the favour and contact someone with knowledge of local legislation and as well with sufficient knowledge of systems like that.

Over in Europe in some countries you can fit a fully pumped system of a stove.
Provided that you have a mains pressurized emergency heat leak fitted above via gravity.

For the ones not having any idea what that is:
It is a steel cylinder with a coil inside. Obviously you have your flow/return and you have a connection to the mains and a discharge. The mains side has a valve with a remote temperature sensor (bit like an oil fire valve but self resetting).
In case of an over temperature occurrence the valve opens and the mains water cools the heat leak down.

Have not seen anything like it here and would not be aware of it being legally fitted over here, someone in the know?

To the OP again: you are building a ticking time bomb with your system as you have planned. I have a customer who survived a back boiler blasting out the wall. And I have not heard anything about repeating that soon. The next time would be the end anyway as the body can only compensate so and so much of burned skin. Or should I say boiled?
Have a read about pressures and boiling points and compare how fast you can run with the expansion rate of steam and the volume of steam produced should it blow off and therefore reduce the pressure suddenly at way above 100 degC.

 

[Howsie]

Online 43 mins ago and not a peep. :30:

 

[WHPES]

Almost missed this

conundrum for a professional plumber

You gotta be joking mate!

It's not a conundrum at all, it's a definite no-no, no doubt about that whatsoever for a professional plumber

 

[ukkid76]

Ok so I'll take it as a no no..... that means I'll fit it as a separate system I'll separate the radiators from the combi keeping the two downstairs on the combi system and re pipe the upstairs ones to a vented system through the wood burning stove,

I just thought their may have been a way of doing it as an all in one system.....

As for using local qualified plumbers around here I'm sorry but I've seen loads on installations that have made me cringe....

Or there is always the option of purchasing a standalone wood burner or converting this one......

Thanks for the replies...

 

[AWheating]

your best option if the cold supply is ok is to fit a thermal store, the problem is if the wood burning stove is not fitted correctly it will be dangerous. you cant just run a few rads off it, it has to have gravity circulation and energy storage that is capable of removing the heat energy from the stove without the radiators running or the electric being available otherwise it may go bang.

this is why they should only be fitted by competent people.

 

[DirksPlumbing]

your best option if the cold supply is ok is to fit a thermal store, the problem is if the wood burning stove is not fitted correctly it will be dangerous. you cant just run a few rads off it, it has to have gravity circulation and energy storage that is capable of removing the heat energy from the stove without the radiators running or the electric being available otherwise it may go bang.

this is why they should only be fitted by competent people.

Check with a local experienced fitter if emergency heat leaks would be an option there. As this allows you to do something similar what you had planned. But do yourself a favour and have everything gravity related installed by a professional (safety). Do not touch this part of the system yourself. And do not attempt to design this yourself either. If your radiator system is sealed then a heat exchanger could be the answer to integrate it into the stove system. There are solar units available that would be able to do the job. Just be aware to maintain the water quality in both systems to ensure a reasonable efficiency.

The thermal store would indeed be a good solution if you have the space and would even allow you to integrate for example solar with ease. Just it would need to be big enough and located suitably.

But again I would refer to local installers as they have a much better insight in local legislation as well as conditions.
The climatic conditions in Italy do differ a lot from British and therefore things designed for Britain may just simply not work sufficiently or be unsafe in Italy.

A great example would be the british way of guttering/downpiping. Because of the large temperature span it would just crack and crumble away on the continent or "walk" off the hooks. As well as it would not cope with a normal rain to start with.