On Mon, 7 Feb 2005 00:43:23 +0000 (UTC), "Alex"
wrote:

A System Boiler (SXI) for use with sealed systems where there is a need to
retain the traditional hot water storage and central heating systems.

The above is quoted from the glow worm website there words not mine

This doesn't mean that system boilers are only meant to be used in
systems with pressurised hot water storage.

As mentioned before, a system boiler is just a regular sealed system
boiler with the inclusion of a pressure vessel, pump, and a pressure
release value already plumbed and wired within the casing of the
boiler.

This is mainly just to make installation into a new sealed system, or
an existing open system thats being converted to a sealed system,
simpler, quicker and cheaper.

The main disadvantage is that you cant then choose the size of pump
and pressure vessel to suit a non typical system, and the case of the
boiler is typically a fair bit bigger.