On Fri, 16 Jul 2004 20:57:38 +0100, Set Square wrote:

I would expect the steam to come out through the vent pipe and to
fill the attic with steam rather than heating the header tank
snip
Am I overlooking something?

When a cylinder boils the expanding steam in the cylinder forces hot
water out of the vent pipe and thus into the header tank. Normally
making loudish thumps and bangs as it does it.

--
Cheers
Dave. pam is missing e-mail