Idiot level leaking radiator valve question

I assume the nut on the copper pipe?

Yup, usually does the trick.

Clockwise.

Best to hold the valve steady. I use Mole grips horizontally to counteract the motion of the wrench.

Should be fine, just go steady, a bit at a time.

That will be clockwise when looking upwards:-)

It looks like microbore. Sometimes a little tightening up will not work. They can be bastards those 15mm to 10mm reducing valves.

Adam

The Medway Handyman explained on 26/04/2010 :

Holding the TRV body with something else to brace it, the lower nut just above the copper needs to be turned from the left towards the right. Try tightening it by one complete face of the hex (1/6 of a turn) and then see how it goes.

I've had 2 instances of slight leaks from radiator valves on 10mm pipe like that, the slightest disturbance is enough to start them weeping. In both cases there was no immediate improvement after quite drastic tightening but the leak did stop after a day or two. You'd probably be best to only tighten up a little to start with and if it has no effect give it a day and then try a bit more.

Sort of! Clockwise in worm's-eye view, counterclockwise in bird's-eye view!

Thanks to all who helped. Have managed to get it tightened up, without any problems.