harry wrote in news:56002e72-ef88-4af1-bac1-
:

Why not get a water softener and all you need then is salt?

That's an idea; thanks. I've just been searching for a conversation I had
about this subject a few years ago, and there was a heated (and
inconclusive) debate about whether phosphate dosers and water softeners
were more effective than ion exchange water softeners. No-one involved in
the discussion could point to any controlled tests to back up their
opinions. Anyone got any educated (or fist-hand experience) opinions on
this question?

In a previous house, I installed a phosphate doser, thinking it would
prevent my heat exchanger from scaling up. One year later my boiler's
heat exchanger was clogged again, as it had done almost every year
previously. Having said that, I think it was partly clogged with iron
oxide (i.e., black rust). Perhaps water softeners don't inhibit the
formation of iron oxide. Is there anything that inhibits the formation of
iron oxide, as well as limescale, in heat exchangers (apart from things
like Fernox, which obviously can't be added to mains drinking water.

A