Radiator TRV leak

shiraz99

Can I get some advice regarding a leaky TRV. The water is seeping up from the pin rather than the gland nut so not sure if there's anything I can do to fix it. Generally happens if I set the TRV to anything below 5 but if I leave it at maximum the leak will eventually go away. I've tried tightening the gland nut but this doesn't really do anything. I'm not sure whether I can replace the gland seal or just replace the TRV.

It's a Pegler Bulldog TRV so the pin isn't a pin as such but more conical, see attached image.

bjorn_toby_wilde

https://forums.moneysavingexpert.com/discussion/6660332/radiator-trv-leak

I don’t think they’re serviceable but they’re pretty cheap to buy. If you tried to service it you’d have the same problem as if you replaced it, namely draining down.

I haven’t replaced one but I believe it can be done without draining the system provided you work very quickly.

Our plumber replaced one for me and it took him about 3/4 of an hour. He didn’t drain down but I didn’t watch how he did it.

WIAWSNB

As btw suggests, there is every chance you can swap this with literally no issues.

I'd buy an identical replacement, and undo the chrome nut. The removed part will hopefully include all the working bits - the gland nut, pin, washer - all intact in one piece. Then all you need to do is swap it with the leaking one...

Pressurised system? Cool. Bleed the rad until the pressure is zero - no more water comes out. Fully shut the lockshield, but make sure you count the exact number of turns this takes. Retighten the bleed screw.

Slacken the same chrome nut of the valve on the rad, until it can be undone by hand. Shallow tray and/or towel underneath, then quickly remove the old part, and stick on the new. Almost certainly the surprise will be the lack of water.

shiraz99

https://forums.moneysavingexpert.com/discussion/comment/81928763#Comment_81928763

I don't think that chrome bit below the brass gland nut is actually a nut at all. I think it's just shaped that way so you can use a spanner/adjustable on it as a brace whilst undoing the gland nut above it. I've got a replacement coming (ordered but currently out of stock at my local Wolesley) so I'll have a closer look with that one first.

WIAWSNB

https://forums.moneysavingexpert.com/discussion/comment/81929006#Comment_81929006

D'oh!, if so.

What I assumed was a seam may just be the thread for the TRV head?

In that case, the internals must be pretty small diameter as they cannot be any larger than the brass gland nut.

You'll soon know, and it should just mean you undo the brass nut instead, and remove the moving parts of the valve as part of that.

You'll soon know, but the same applies - depressurise fully, reclose the bleed screw, swap in two seconds.

I expect there will be a compression spring under the washer - check how easy it is to extract this too. And, it'll want to.push the internals out as soon as the brass nut releases it's last thread :-)

Experiment with the new fitting.