On 24/10/2020 11:14, Dave Plowman (News) wrote:
In article ,
wrote:
On 23/10/2020 18:46, Dave Plowman (News) wrote:
In article ,
wrote:
On 23/10/2020 16:14, Dave Plowman (News) wrote:
In article direct.com,
mafj wrote:
Recent research that in UK households with combis kitchen water use is 2.5 higher than other systems. (18L vs 7.2L per person per day).
And the most likely reason pointed out is time for HW to arrive).

So secondary loop of any sort would seem to help alleviate this waste.

Not sure circulating water within a potable supply is either allowed or a
good idea. And just when were we short of water in the UK?

DHW circulation is standard in larger buildings, without it there would
be huge water wastage as people wait for hot water to reach the taps. I
control mine with a pipe stat and a timer.

But that will be from a storage system. A combi is connected to mains
water.

True, I was responding to your comment and didn't spot that the subject
was about combi boilers.

Didn't potable water give you a clue?

You can circulate a stored system in a house to give quicker hot from a
tap. Whether it is worth it in cash terms, I doubt it.

Errr ... my hot water is potable, is on a circulation loop, and is based
on a 300 litre unvented cylinder. Search for potable dhw circulation
pump for more info.
I agree that it's probably not financially worthwhile to have a
circulation loop, but in a large house (or hotel) it's a convenience
that's worth paying for. My boiler and DHW cylinder are in a plant room
(the old coal store) with quite long runs to the furthest bedroom and
bathroom; when the circulation pump is off it can take a very long time
to get hot water out of the tap or shower.