F wrote:
"Mike Faithfull" wrote in
:


Just had a major overhaul of the CH system and the plumber pointed out
the same problem to me - 2 rads on a drop from above with no drain
cock. So, as part of the overhaul included fitting TRVs and new
lockshields, he fitted one of the 'special' type. The valve is kind
of like a tee where the 'leg' attaches to the pipe, one end of the
'crossbar' attaches to the rad, and the other end of the crossbar is
the drain point.


Thanks. This sounds similar to, but not the same as, a couple of
lockshields I have found at Screwfix - 11074-47 and 82588-47.

Anyone got any views on relative merits?

Of the rads I've come across with drain-off valves, and regular drain
cocks in general, a large proportion have been either stuck (and won't
drain) or the rubber washers have perished and fall apart when you
disturb the cock and won't shut tight again leaving you with water
p****ing out over the customer's nice clean carpets :-(.

KISS. A rad can be drained from the valve/radiator unions (as long as
there's room to get a shallow tray underneath) and you should have to do
this so infrequently that the added complication (and unreliability) of
a drain cock isn't worth it. Plus they look shyte :-)