In message , at 11:18:26 on Sat, 31 Oct
2020, "Dave Plowman (News)" remarked:
In article ,
Roland Perry wrote:
In message , at 21:11:37 on Fri, 30 Oct
2020, thescullster remarked:
Roland Perry Wrote in message:
In message , at 11:46:26 on Fri, 30 Oct
2020, thescullster remarked:Roland Perry
Wrote in message: Struggling to find the
keywords to guide me to buy online those plumbing gadgets which
clamp on the outside of, and pierce through, existing pipework to
attach a dishwasher feed or something similar.-- Roland PerryIf
you are fitting a drain valve to empty the whole system, then this
should be one that allows good flow.That way there's a chance the
water velocity will carry crud with it .The "pipe cutter" types will
not do this for you.I'm using the pipe-cutter valve to empty the
system, so that I can put a more conventional bleed-valve
elsewhere.-- Roland Perry

As has been mentioned the "proper" one that you fit should be at
the lowest point on the system so that you can empty ground floor
mains if necessary.

Yes, that's the plan; although strictly speaking the lowest point is
under the floor, so the best I can do is just above that.

In practice, you rarely need to drain down to the last drop. Just low
enough to allow the removal of radiators for decorating etc. The boiler
and bits are usually higher than the lowest rad too.

Yes, my boiler's upstairs. And I have no rads in the attic (you may
laugh, but a loft conversion I did 15yrs ago was supposed to, however
the builder chickened out and we had to use electric [oil filled] ones
instead).

What left a bad taste in the mouth was he initially didn't allow
anything off the bill for failing to do the wet plumbing and supply of
rads, but charged "extra" for fitting the electric ones, which I had
incidentally free issued to him.

Grade A plonker!
--
Roland Perry