On Sat, 05 Jun 2010 10:50:56 +0100, Dave Plowman (News) wrote:

Wonder how much 'iron' there is in a modern central heating system?

The only real change in domestic CH systems for the last few decades
has been the move to low capacity boilers with heat exchangers made
of ali. Copper tube and steel radiators have remained pretty much
unchanged.

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Cheers
Dave.