In article ,
RJH writes:
On 19/01/2015 13:15, CB wrote:
On 19/01/2015 12:40, Ron wrote:
Would it cost more to run central heating with an unvented hot water
cylinder and system boiler or a combi boiler with no HWC?

R.
In my opinion yes. All other things being equal there will be some heat
lost from the hot water cylinder which in summer will be wasted.


I think the 'all other things equal' would need to be qualified. For
example, I've got a dishwasher and an electric shower, so need very
little hot water from the boiler. And not everyone needs (or wants) a
room heated by the cylinder.

Yep, and things like number of people in the house, how predictable
their occupancy is, etc.

If you have a very predictable load, say, 3 showers every morning,
you can ensure the cylinder is heated up ready. OTOH, if the load
is very unpredictable, away half the week but different days, only
one person, etc, then you will end up wasting some of the hot water
and/or maybe not having it when you want it.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]