robgraham wrote:
On 27 Oct, 13:30, "dennis@home" wrote:
"Dave Plowman (News)" wrote in ...

No reason why you couldn't heat a cylinder from a combi. And keep the
'instant' feature for the kitchen tap.

Interesting - I've yet to find a combi supplied kitchen tap that was
'instant'.

I have a traditional system, and get hot water through in reasonable
time and with good flow - I think every house I've been into in which
the hot water is combi supplied, the wait has been extensive and the
flow weak.
Correct.

You need something like a 50KW combi to heat hot water really fast.

Which then needs to run at much less to do CH. Which is why the better
designs modulate down. But even so, efficiency is poor.

And the requrements are quite different as well. Optimal outflow for
modern radiators in not freezing temps might be as low as 35-40C.

Optimum hot water as far as I am concerned is 60C or so.

Rob