Leaking radiator valve connection

tonkski wrote in news:8db6369b-62bd-4f3c-8490- snipped-for-privacy@googlegroups.com:

It looks like the extension is merely shoved in and gunged to seal it. Something missing I think.

Sounds like the adjustable tail has failed in some way and lifting it changes the fit of that stem but it could be almost any other part of the assembly. Adjustable tails normally mean the rad has replaced an old imperial one, but you can get fixed-length versions ('extending unions') that should be more robust. You have to get the right length (smaller is better than longer) but they don't have the slide-y bit that causes this problem.

It shouldn't take too much to fix:

Cover everything well to contain the inevitable leaks of black gunge. Close the valves down. Count the number of turns on the lockshield end (the one in the photo), so you can re-instate it at the end of the job. Sometimes, a thermostatic valve doesn't close completely (if there's one on the other end). Taking the head off and putting a spacer under the control (a penny works well) will close it completely. Open the bleed valve to let any pressure out, then close it again. Loosen the union between the valve and the radiator stem (the chewed up chrome one in the photo) at each end by half a turn or so. This should let you lift the radiator off its brackets (hopefully there will be enough play in the pipework) and lay it down without leaking too much. Open the unions completely and (with a bit of luck) you can carry the radiator outside upside down to drain it where you won't make too much mess. It would be a good idea to flush the radiator out while it's off or, depending on its state etc, you may see this as an opportunity to replace it with a new one. Put a new tail on, and reassemble. Open the valves, check for leaks and bleed the radiator to refill it (if the system is pressurised you'll probably need to add more water/pressurise the system).

Thanks for your replies both. Doesn't sound too onerous, though I wonder why the extension was gunged in. No doubt I'll find out....

tonkski wrote in news: snipped-for-privacy@googlegroups.com:

Could the thread be damaged - or was it merely a bodge.

You'll certainly need to dismantle the tail to see what's going on, and possibly replace it. To do this, you'll need to drain the radiator. Whilst the approach described by GMM *might* work, there are too many things which could wrong - leaving lots of indelible black gunge all over your carpets. It's far safer to drain the radiator in situ whilst it's still securely hanging on its brackets.

Put some old towels under both tails. Turn both valves fully off. Open the bleed screw. Get a large washing-up bowl to receive the water from the rad. Get a foil food container (e.g. as used for Chinese take-away) and hold it under one of the tail to valve union nuts. Slacken the nut until water runs into the foil container. When the container is full, nip up the nut by hand and empty the container into the bowl. Keep doing that until no more water comes out - and do the same to the other valve, where a drop more may come out. When the radiator is empty, fully undo both union nuts and lift it off its brackets.

WARNING: there will still be some black gunge in the bottom of the radiator below the level of the tails. To get rid of this. hold the rad with one tail over the bowl, and slightly raise the other end. Finally, stuff some kitchen roll into both tails before carrying the rad outside.

Thanks Roger. Fortunately the radiator is in the kitchen, with no carpet, so a little black sludge on the floor is OK but I'll follow your suggestion.

I only come on this forum when I have a problem these days, so I'd wondered if it might be a bit quiet. What a great response I've had.

and

alan_m wrote in news:co3gfvFipfU1 @mid.individual.net:

Why do people assume the lockshield was set correctly in the first place?

Another tip is to have a wet vacuum cleaner to hand if you have one.