Stephen Jones wrote:
I have a very old microbore vented central heating system and I need
to remove a radiator whiles the wall its mounted on is removed. I
wondered if instead of draining the system I could conpress the pipes
, cut then bend to seal, maybe solder ? Also what size pipe is old
microbore. It looks around 8mm but everything else in the system is
not metric so I don't suspect this is. (1/2" and 3/4"). Also can you
get fittings to fit a new radiator onto the old system. It will
eventually all be replaced when I have more money

I did this with a radiator I wished to remove (room warm enough,
in irritating place.
Took a pair of sturdy mole-grips, two bits of flat steel 1cm*4cm, and
squashed the pipe between them.
Removed radiator (after draining using plugs), with a trimmed ice-cream
container used to collect remaining water after unscrewing pipes.
Resulted in a couple of drops per second.
When the radiator was removed, there was better access, so I could flatten
the pipes better, then they were bent over at the flat portion, and
recompressed.
Has not dripped since.