On 14/11/2016 13:43, Andrew Gabriel wrote:
Added a new radiator at the weekend, to a vented system which I had
recently added new inhibitor. New rad is on top floor and I had laid
on the pipework previously, so only a towel rail needed draining,
and the expansion tank. Not wanting to lose the inhibitor in the
expansion tank, I wanted to plug the outlet. Hunted around, and then
hit on the idea of using the plug of silicone which sets in the nozzle
of a silicone gun tube. Blew the plug out backwards with a compressed
air can, and it worked perfectly.

Genius.
I'll save the next ones I come across and put them in my plumbing box
for future use.

Great tip.