On Sat, 12 Apr 2008 10:00:53 GMT, a particular chimpanzee, "neverwas"
randomly hit the keyboard and produced:

Me too; and as we are still contemplating a new boiler I
also looked. But it looks as if it is (sort of) true.
....
But isn't there a bit more in the BR_PDF_PTL_DOMHEAT.pdf?
Eg Table 1 *does* include (row d para d) that "where the
mains water hardness exceeds 200ppm provision should be made
to treat the feed water to water heaters and the hot water
circuit of combination boilers to reduce the rate of
accumulation of lime scale”. And that's domestic GFCH.

I have no idea whether this is justified. But with sealed
systems needing so little water added I do wonder if it is
another bit of over-regulation which has been slipped
through - possibly as a result self of another of the then
Deputy Prime Minister's lot being captured by a
lobby-group?

I must admit, I wasn't aware of this, but then I work in an area where
all that comes out of our taps is lovely, soft mountain dew.

The legal requirement is, "Reasonable provision shall be made for the
conservation of fuel and power in buildings by...limiting heat gains
and losses...from pipes, ducts and vessels used for space
heating...and hot water services".

Guidance on how to do this is given in Approved Document L1B
(Conservation of Fuel and Power in Existing Dwellings). This
references the Domestic Heating Guide, which as you've pointed out,
does contain that paragraph above. It doesn't say that a water
softener (or other form of treatment) must be provided to the closed
loop part of a boiler but to the 'feed water' to a water heater and
the 'hot water circuit of a combination boiler', in other words, the
stuff that eventually comes out of the taps.

If one does not follow this guidance, one has to demonstrate that any
alternative chosen gives "reasonable provision" to limit the losses
due to furring-up of pipes. If electro-magnets, Teflon pipes or
sacrificing chickens can be shown to work, then they can be used as an
alternative.

Under Schedule 2A of the Regulations, there are a number of 'competent
persons' schemes, which include the installation of hot water service
systems by CORGI, HETAS, NICEIC et al.
--
Hugo Nebula
"If no-one on the internet wants a piece of this,
just how far from the pack have you strayed?"