It seems to be a common recommentation Vers les chaudières au biofioul | Blog
Parmi les points de vigilance soulevés par Viessmann, le plus important est le remplacement des conduites en cuivre par des canalisations en aluminium ou acier inoxydable, sous peine d’une oxydation et dégradation du biofioul. Parmi les travaux de mise en conformité de l’installation figurent notamment le nettoyage ou le remplacement de la cuve de stockage et l’adaptation du réseau de chauffage (bitube plutôt que monotube).
So what Viessmann is saying is that the use of copper pipe damages the chemical make up of the biofuel itself. Interesting, but presumably the fuel would have to remain stopped in the pipe for a period of time for this to happen. I wonder if overnight would be long enough for example.
When Viessmann talks about “adapting the heating network”, I wonder exactly what it is that is meant by this. The item refers to “two pipes rather than one pipe”, but then my system already has two pipes connecting the fuel tank to the boiler (one for the feed, and one to return the excess feed back into the tank), and of course the heat distribution network already has both flow and return pipes.
In general, I think that it is necessary to use very exact language in relation to this subject in order to avoid confusion. For example; Fuel and Fioul are words which do not have the same meaning. I wonder also as to whether ‘bitube’ means two separate pipes running along side each other, or does it refer to tube that is made out of a composite of two different materials. Sometimes these very important technical differences can be lost in translation…
Perhaps someone could review the scientific and popular literature?
It is also a potential problem in vehicle fuels
Corrosion – in long term storage, fuel containing Ethanol can become acidic and cause corrosion of aluminium, zinc and galvanised materials, brass, copper and lead/tin coated steels.
Robert - thank you for a very comprehensive and informative reply.
Our installation sounds very similar to yours, with a bolt-on burner. Because of the size of our house we have 21 radiators, valved into three sections, two of which are isolated most of the time, being used only when family or friends stay in the colder weather (hence not very ofted!), and all radiators have thermostatic valves fitted.
Replacing copper feed pipes wouldn’t be a problem for me, although I’m not sure what metal the pick up pipe in the storage tank (2500ltrs) is. Again, a not insurmountable problem.
I had been looking at changing to a heat pump, but in view of the size of our installation and the cost of the change, and living in a very old (large, obviously) house, I doubt I would ever get my money back, even with any possible subsidy.
Thanks again.
it is possible to survive… we did, for 2 years.
Electric kettle for washing/washing-up et al… and OH fitted a cheap, instant-electric shower (coldwater feed)… in the laundry room… (that was easily dismantled later and freely given to a young couple who were in dire need)
If this is going to take you a while to get sorted I suggest you first clean and sort out 1 room that you can use for comfort and sort out making it warm - pounce from end September and in October quickly on that. As bricos (DIY) here are very seasonal so stuff comes in for the season and when it’s gone it’s gone and whatever they say, they won’t re-order for the rest of the season.
@Deuxanes You are welcome. It seems that our current heating systems have a lot in common. Hope you don’t mind but I’m going to PM you with some further info.
Robert.
I must be getting old because the cost of doing anything shocks me. My enthusiasm to replace my pool cover now 15 years old soon faded when the quote was 20k. Luckily I broke my old heating system myself when chipping ice off it in winter with a screwdriver and punctured the coolant line. So my relatively new 10 years old system only cost €12k. Could it be cheaper to buy a kit house from Germany with a net zero energy rating and find a cheap (and nice) place to put it…
Surely the entire cost of replacing it with an equivalent non fossil fuel boiler should be borne by the vendors unless it can be repaired. Even then a view should be taken as to whether it’s worth repairing. I would ask for 30k for the boiler plus at least that again for the replacement radiators to be taken from the sake price. The vendors clearly knew they had a problem and therefore they should pay.
I wouldn’t expect a vendor to go for that - had the house been being sold with a brand new boiler and heating system the sale price would have been higher.
A contribution towards the replacement or paying the full repair cost would seem fair.
