difficult bleed screw

Easiest thing may be to replace the whole valve. Have a look at part number 6918 at

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.

I measure a standard rad key as 5.38mm, and the rad nipple as 5.25mm [1] So I would try a new key first, otherwise a No 10 clock key which is 4.75mm fits most buggered nipples.From here

In message , asalcedo writes

Perhaps the Subject should have been "Bleeding difficult screw"

Hi Mark,

I like your observation about standards in plumbing.

I have measured the rad nipple and it is 4.9mm in my case (in one tha I can undo without a problem with my 5.8mm key)

If you tell me your rad key is 5.38mm then I am certainly a lot close to solving the problem by shopping around with my caliper in hand.

I certainly need this radiator, it is in my office and it does not ge warm enough these days.

Thanks,

Antoni

-- asalcedo

Thank you John. That is a good idea. If Mark's suggestions above do no work, I will try that.

Regards,

Antoni

-- asalcedo

Hi Mark,

I found a new key, 5.1 mm, that worked a treat.

Thank you very much

Antoni

-- asalcedo