On Sun, 05 Sep 2004 22:18:04 +0100, Set Square wrote:

In an earlier contribution to this discussion,
Ed Sirett wrote:

On Sat, 04 Sep 2004 23:03:38 +0100, Set Square wrote:


However, in cases where a system already exists - using a
conventional boiler and stored hot water - there would, in my view,
have to be some pretty exceptional circumstances to warrant
converting to a combi-based system.

A typical dwelling where a combi might well be the best approach is:

A 1 bed flat built in 1975 which has a Arcopack (sp?) and a life
expired conventional boiler.
The Arcopack unit is pre-plumbed steel contraption with a steel CW
cistern and an insulated copper HW tank/cylinder) in the lower
section. Typically a small F&E header tank is provided inside the
upper part of the cistern for the primary circuit.
Flow rates to the bath are moderate and there is no (I don't mean
little) pressure for a shower.

The mains is plastic but only 1/2"/20mm. Good enough for a combi but
debatable for unvented.

The cupboard space is relatively more valuable in a small flat. The
maximum occupation is likely to be a couple + very small kid.

You will not likely rent out any such flat in the middle market
private sector without a shower.

The combi will only be a little larger than the old boiler.

Booster pumps can cause noise problems leading to serious conflict
between neighbours.

The case for a combi is fairly strong in the above scenario.


Agreed - there will be specific (dare I say "exceptional"?) circumstances
where a combi is the appropriate solution.

However, *in general*, I believe that replacing a conventional boiler with a
combi *doesn't* make sense.

You may well be right. Perhaps I see a somewhat skewed picture of UK
housing since a big part of my work is middle to up market private rented
flats.

--
Ed Sirett - Property maintainer and registered gas fitter.
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