Pipes showing green patches - 18mths after installation

[Snowdrop]

Pipes are showing a lot of green patches, 18mths after installing a new heating system and water pipes. These pipes are in airing cupboard and by boiler. There is green around most of the joins of the pipes - ie where 2 pipes have been soldered together. Also spots and patches of green on pipes. Also green on the gas pipe to the boiler. The green has been cleaned off as it is on the outside of the pipe.

The cold water pipe to the shower pump has already had 3 pinhole leaks from areas which were green – The pipe has been replaced.

I have read about excessive flux causing corrosion where the pipes have been soldered. Could this have caused the green around the joins? However I don’t understand what the other spots and patches of green are.

Would any one be able to offer any more information about how the green could have occurred.
I am assuming the green is corrosion.

So far the current remedy of the installer is to clean the pipes.
However:
In my view this is not a permanent solution
Will the corrosion come back or continue even after it has been cleaned off?
Will more corrosion occur in the future?
If the corrosion is not cleaned off I am assuming the pipe will corrode through to cause a leak?
Would there be corrosion on the inside of the pipes?

What is the solution? Should ALL the pipes which are showing corrosion be changed?

Thank you for any replies.

 

[Rckape]

Hi Snowdrop, you are correct in that it is likely to be excessive flux or insufficient cleaning following soldering corroding the copper.

The green is evidence that the copper is effectively being eaten.

The other spots are from nearby soldered joints or possibly the plumbers hands/equipment.

Once properly cleaned it should halt any further corrosion.

The pipe having solder residue doesn't automatically mean that it will pin hole. I've seen pipes over 30 years old that have not been cleaned properly and still been ok.

The water on the inside of the pipe will wash away the internal flux. The fluxing process for gas joints is different to reduce the risk of corrosion (plus there's no oxygen to accelerate the reaction).

In my opinion you needn't have all the pipes replaced. If you're still concerned I'd recommend getting another plumber in to give you an opinion having seen the issue in person.

 

[plumben]

as above really
It sounds like the original installed was too lazy to have a wet rag and wipe down his work once soldered,
but thats alls it is, excess flux that was not cleaned off, if you clean all the pipes with water to remove excess and then rub with either wire wool or emery cloth to removed anything thats left

 

[Rickster123]

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