YAPH writes:

On Wed, 25 Feb 2009 15:18:29 +0000, Jon Fairbairn wrote:

If I'd had one fitted (instead of the stupid magnet that the
installers insisted on fitting, and in which I never had the
slightest confidence) at the start, I might be about to
break even. If I fit one now, what are the chances that the
rest of the boiler will still be going in six years?

Screwfix do a phosphate dosing one for about £35 - single stage
whole-house scale inhibitor. Refills about £15 but much bigger & should
last longer than Combimate (combimate refills are about £20).

Thanks. Is that 68371? (£40 now) it looks less pretentious
than the Combimate, too. The refills seem to be about £25,
though, so I get 5*25+40 = £165, which is better than the
Combimate, but still suspiciously close to the cost of
replacing the exchanger! [The Screwfix description says "12
month cartridge life", though of course it could last
longer]

One question about either of these is that they say "Must be
fitted away from direct heat. " The boiler (Ideal Isar¹) case
doesn't get that warm, but it's in a cupboard, so gets
significantly warmer than ambient. Would that be a problem?


[1] Don't say anything!

--
Jón Fairbairn
http://www.chaos.org.uk/~jf/Stuff-I-dont-want.html (updated 2009-01-31)