"Heliotrope Smith" wrote in message
...

"Steve" wrote in message
...
I'm upgrading the plumbing prior to having a Combi installed. I'm going
to
put in a number of (full bore) isolation valves on both the DHW and
..
snip
..
Valves are usually compression fit so make the solder joint first then fit
valve.
With drain cocks and the like then these are dismantled prior to
soldering.

Thanks. But my problem is I need to fit all the valves before the engineer
installs the boiler. So any soldering he does will have to be with the
valves already in the system.