al wrote:
I want to replace some of my rads but am confused about the
measurements.
The units I have are quite small and old. The one in my hallway for
example
is 600mm wide across the actual body, but 700mm across from the
extremity of
each tap/joint/whatever you call it just before where it meets the
T-junction for the house pipes.

Looking on Screwfix, the widths available are 300mm, 500mm and 600mm.
It
also seems like those radiators are the same width body as the place
where
the pipe would join, unless there's something you screw in that makes
up the
distance ..?

The bits that screw in the radiator are part of the valve rather than
being part of the rad so the width you want in your case is 600. When
you put new valves on really make sure they've sealed properly!


I'm confused - what should I be measuring? Also, does anyone have a
good
recommendation for a web-guide to replacing rads? I'm going to get
help
from a mate putting a new one in where the pipes need cutting, but
was
hoping to do straightforward direct replacement myself before going
as far
as draining the system.

Close off the valve at each end, drain the rad in whatever way,
disconnect the valve from the rad at the obvious joint, carefully
remove rad. Now either remove the other part of the rad valve from the
old rad or get a new one and put it in the new rad. Refitting is the
reverse of removal etc.