On Tue, 9 Mar 2004 21:23:02 -0000, "IMM" wrote:

Firstly, a combi is a "combination" of the heating and water system in one
case, eliminating external tanks and cylinders, and generally supply hot
water at high main pressure.

Does this mean that all the radiators are at mains pressure? If so,
does changing from a conventional system to a combi mean replacing all
the radiators?

Jim