# BOILERS - COMBINED WOOD/PELLET and SOLAR



## duogatti (Jul 13, 2015)

OILERS!



Can anyone give advice on sourcing a boiler system that can use both logs AND pellets? I've just bought a house in Piemonte and the boiler needs to be replaced. We are surrounded by trees and have piles of logs already, but need a system that can also start automatically if we're not at the house (to stop pipes freezing in the colder months).

Any recommendations? 

Also, we're looking to install a gas/GPL boiler for hot water but have heard about solar-powered hot water boilers - any experience of these out there?



Many thanks!


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## Bevdeforges (Nov 16, 2007)

> Also, we're looking to install a gas/GPL boiler for hot water but have heard about solar-powered hot water boilers - any experience of these out there?


We installed a solar assisted water heater a few years ago. It is basically an electric water heater, but with big solar tubes that collect sunlight (not photovoltaic cells - black tubes filled with a heat collecting liquid). It works great - but needs actual sunshine, not just general sunlight (on a cloudy day, for example). With a bit of sun, it uses very little electricity, even in the winter. I suppose the main electricity use is to circulate the heating fluid and operating the various regulating devices that are part of the set-up. 

We did find, however, that you need a sort of water softener to remove the calc from the water entering the tank. Without one, if you've got hard water, the joints seem to develop leaks. But once that was fixed, all is well.
Cheers,
Bev


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## NickZ (Jun 26, 2009)

Well IMHO you're making your life too complicated and therefore expensive.

Do you have natural gas at home? A gas boiler isn't going to be more expensive then a pellet boiler to buy. There are models that can be controlled by your phone. 

OTOH if the house has a freeze risk it's foolish to leave the pipes full of water. Turn off the main tap entering the house. Drain the pipes. Done. With your idea what happens if there is a break down? Or if the power goes out? The other thing is ask your neighbours I bet a few know of unoccupied winter homes. They aren't kept heated.

I'm sure somebody makes a combo boiler that can take wood and pellets but the thing will be expensive. It might be cheaper to get one of each and I'm not kidding. 

Perversely solar might not make sense for only summer use. Even if you get an electric only boiler it'll likely not use that much energy during the summer to justify the expense of a solar hotwater tank.

OTOH if you combine the solar water tank with your heating system then it might be a great idea. With in floor heating the tubing only needs to run at about 40C. The solar would do some of the work heating it. If you're lucky during the shoulder months it would do the majority. The other main source (wood,pellet,gas whatever) would kick in and raise the temperature the rest of the 
way.

Problem the above implies replacing your flooring. It'll work with normal wall radiators but less well.


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## GeordieBorn (Jul 15, 2016)

I think a major problem with leaving it is electric failure (quite common here) and the need to re-fill the fuel. You can get pellet boilers that automatically light, so I would guess there may be a boiler out there that could light by pellet and switch to log, but there is still the problem of the electrics and refuelling. We have a sansa (olive waste) boiler with a very large hopper, but even staking it up to the hilt, I doubt it could last much more than 2 weeks. It does automatically light, but it will re-light after being off up to about 24hrs. However, apart from the above it would also likely need cleaning after say a month or so. If it is mainly a holiday home I think you are looking at having someone maintain it or draining whatever system you eventually get. If you do the latter, I would be looking at a wood burner and solar.
There was a guy on another forum who is a real expert in this field and used to live and work here installing systems. He went back to the UK, but last I heard he was still travelling over to do installations here, I’ll see if I can dig out any more details.


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## duogatti (Jul 13, 2015)

Thanks everyone. We'll be living here permanently so not leaving the house for weeks on end - just potentially a week or so for a longer trip back to the UK. 

We're likely to go with pellet boiler backed up by gas, and then have GPL tank for hot water. Solar we're looking into as we're south facing with a bit of land but I'm conscious of the upfront costs and that we may never get the investment back! 

Still exploring so any further opinions are welcome. Thanks all.


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## GeordieBorn (Jul 15, 2016)

Have a look at bio boilers on a search and it will come up with UK type solutions and then you can translate to Italian. A few weeks away and you could possible (watching forecasts) find something to cover you, more than 2-3 weeks is a different thing.


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## NickZ (Jun 26, 2009)

If you're spending the money on a methane/natural gas burner it'll be hard to save enough on pellets to justify the pellet boiler. Worse you've got two systems that depend on electrical power. If you have a winter blackout you'll have two new boilers and no heat.

If you have free wood a wood stove is a no brainier. You can also get a wood boiler but that will require power. A small wood stove that can keep part of the home warm no matter what isn't a bad idea.


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## baldilocks (Mar 7, 2010)

It is doubtful that you will find a unit that will burn both logs and pellet since the combustion methods are different. 

We have a log burner that heats half the house (it would heat the other half as well if we put in pipework and radiators, but it would require a different type of burner). The log burner is in the lounge and there are ducts, from the top of the burner, that convey hot air to the two bedrooms above. The cavity that contains the stainless steel flue tube has air inlets from the lounge and outlets in the habitable attic thus heating that area 126 m³. We have a solar panel (2m²) for hot water when the sun is hot enough (usually March - November) and an instantaneous gas water heater serving two bathrooms and the kitchen that runs off a LPG bombona. No electricity involved other than the water heater which uses two U2 batteries (last about five years) for ignition.


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## GeordieBorn (Jul 15, 2016)

baldilocks said:


> It is doubtful that you will find a unit that will burn both logs and pellet since the combustion methods are different.
> 
> We have a log burner that heats half the house (it would heat the other half as well if we put in pipework and radiators, but it would require a different type of burner). The log burner is in the lounge and there are ducts, from the top of the burner, that convey hot air to the two bedrooms above. The cavity that contains the stainless steel flue tube has air inlets from the lounge and outlets in the habitable attic thus heating that area 126 m³. We have a solar panel (2m²) for hot water when the sun is hot enough (usually March - November) and an instantaneous gas water heater serving two bathrooms and the kitchen that runs off a LPG bombona. No electricity involved other than the water heater which uses two U2 batteries (last about five years) for ignition.


Have to admit I thought the same until I did a search on "bio boilers log and pellet" and it seems this boiler does exactly that!


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## baldilocks (Mar 7, 2010)

GeordieBorn said:


> Have to admit I thought the same until I did a search on "bio boilers log and pellet" and it seems this boiler does exactly that!


Phew! the price is a bit off-putting. We pay €110 per tonne of logs (ct to size, delivered and stacked in our store) and use about a tonne in a mild winter (such as last one) up to about 2½ tonnes in a really cold one. Financially, that boiler is a non-starter for us.


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