"Andrew Gabriel" wrote in message
...
In article ,
Nick Brooks writes:

It is actually better with flow top, return bottom, gravity or pumped.



Why? Surely it would be better with flow bottom and return top to get
even temperature across the rad

Flow doesn't matter for a pumped system,

No so. In general the flow in a pumped system is on the bottom for
convenience and cosmetic appeal. The work better, pumped or not, when the
flow is on the top of the radiator.