Originally Posted by John Rumm

asalcedo wrote:

The problem radiator has a square bleed screw that is slightly smaller
than 5.8mm and the bleed key does not grab it.

Any ideas how I can turn the bleed screw?

Easiest thing may be to replace the whole valve. Have a look at part
number 6918 at www.bes.ltd.uk (failing that a local plumbers merchant)

If you turn off both rad valves and then undo the whole valve assembly
you should spill little water (of if there is enough air in the rad to
start with then none!). Replace with nice new valve and job done.

--
Cheers,

John.

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