Thanks for the reply - I did blow through the pipe and it didn't *feel" like there was any more water in there although they were a bit damp. When I soldered the fitting it eventually turned blue/black and the solder hadn't taken. I did clean joints thoroughly and use flux etc and have soldered...
Would like advice from any plumbers out there please.
I have just moved a radiator from one side of the room to another. System is drained down and I am tapping into existing pipes (dug down into screed).
My problem is that although I have removed *most* of the water there is still some...