fitting new rad without draining down

[darren bergin]

Is this possible
i Have an unvented cylinder but central heating i think am right in saying is vented because i have a tank in loft
i want to pull a plastic pipe (push fit ) off existing rad to change trv
if i switch off the rad and drain will i be able to pull plastic feed pipe off and quickly put push fit cap on it to stop water flow
seems pheasible to me as the central heating is not a pressurised sealed system
just seeing what you guys think

i know there will be some water

thanks

 

[mogget]

I've got visions of the grab ring in the fitting pulling the insert out with it, and countless other things that could go wrong.

Unless this radiator is somewhere that wouldn't be damaged by a torrent, I think it would be better to drain down. These things rarely go as smoothly as you hope!

 

[John506]

Where on the system is the radiator, high or low?

If it's high then you won't need to drain much anyway, just enough so the water is lower than the rad.

I know I would rather spend another 10mins of my life doing that than even risking a flood.