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Aidan
 
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Default Green deposit on copper pipe at fittings


Dave Plowman (News) wrote:

Doesn't it get diluted by the water to the extent it can't do anything? It
also seems to stop corroding the outside after a while - the reaction
becomes used up.


Unless flushed out &/or neutralised, I believe it makes the water
acidic (pH7) and this then starts off galvanic corrosion with the
steel radiators anode and copper pipes cathode.
If inhibitors are added, you usually wind up with water pH of 8 or 9.

An old fitter commented that they didn't used to have acid flux and he
didn't often see the corrosion problems you get with central heating
these days..