On Fri, 03 Sep 2004 11:03:16 +0100, Pete C
wrote:

On Thu, 02 Sep 2004 22:25:46 +0100, Andy Hall
wrote:

On Thu, 2 Sep 2004 22:19:33 +0100, "IMM" wrote:

None modulate right down to zero. I think the best of them goes to about 5
kW

Mine goes down to 3kW.

Oh well, I suppose it comes down to the cost of an extra heat
exchanger and pump vs the money saved by a cheaper boiler and reduced
boiler cycling.

I'd expect the heat loss when cycling is due to losses from the
boiler's heat exchanger when the water isn't being heated, and
shouldn't be too bad with a modulating condensing boiler using an
aluminium exhanger.

cheers,
Pete.



This was my point. You don't need an extra heat exchanger or pump.

You simply connect the modulating boiler via either a diverter valve
or two (or more) zone valves with one way going to heat the heatbank
and the other to the radiators. The boiler will handle both in
the most efficient way. It is pointless to make it any more
complicated than that.


..andy

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