Dripping radiator nut problem

[reneel]

I have a small problem - one of my radiators is dripping from the nut (slow drip) where the pipe joins the valve. I haven't even had my radiators on. I am not sure if my son or dog has knocked it, or if the olive has just corroded over time etc?

will I need to drain down the whole system to replace the olive? Or can I do anything without the need to drain down. The system is tank fed.

Thanks for your help

 

[TicklyT]

Often a leak at a compression fitting will respond to just a tweak with a spanner, but how tight the nut should be is a matter of experience, developing a 'feel' for how tight is too tight, and when to seek an alternative solution. Overtightening the nut may crush the pipe.

You could try releasing the nut, springing the pipe down a bit, and winding two or three turns of PTFE tape round the olive, or a smear of jet blue or LS-X, and re-fit. Sealant round the threads does nothing on compression fittings - the seal is the olive, the thread just holds it all together.

You may be able to do this without draining the system by shutting the boiler off, bunging the feed and vent, and closing one rad. valve before starting. Expect a bit of water, so have a paint tray and some old towels handy, and be ready to move quickly if anything breaks the vacuum in the system.