On Tue, 12 Dec 2006 17:13:41 +0000 (GMT), Dave Plowman (News) wrote:

If the boiler is off there's no point in the pump running ...

Unless the boiler needs pump overrun which modern low capacity ali ones
generally do. B-)

so the temperature of pipes elsewhere shouldn't make any difference.

Well I suspect that exceeive cooling of the pipes could well set up
gravity flow through the rads, though that would depend a bit on the
layout. Certainly worth insulating the pipes in the void but prehaps
leave a short section un insulated to provide a little background warmth
down there.

--
Cheers
Dave. pam is missing e-mail