In article ,
"jon" writes:
Is this good or bad practice. Should I install isolation valves on the ch
flow and return and the dhw in/out, about 6 inches under the boiler
connections (obviously making allowances for the filling loop and it's
connectors, etc).

Haven't really thought through the benefits of this, or the cons
(un-nessecary restrisctions right at the start of the runs, maybe), but just
thought I'd check with the group.

I'm guessing that there's no real need?

If you buy a fixing jig for a boiler, I think most
include all the isolation valves on the jig. If you
add them separately, make sure you use full-bore valves.
I found them useful whilst installing the system, and
when trying to isolate the location of a leak (which
turned out to be inside the boiler, and contrary to my
initial suspicions, not in any of my plumbing;-).

--
Andrew Gabriel