New Radiator Slow Leak

[GMcD]

All

Just fitted a new rad and annoyingly one the the valve tails has a very slow leak. As I've had to redo pipework to accommodate different size and used compression I'd rather not have to strip everything down again, is there anything I can do (e.g. Fernox Leak Sealer into the top of the rad)? Or is it a case of taking it off again and applying even more PTFE (thought I'd added enough but possibly not). Leak is minscule, drip every half hour!

GMcD

 

[JayJay1978]

Boss white and hemp is very good for this, take it apart again I'm afraid though.

 

[seco services]

for the sake of an hours work i'd rather re-ptfe it, than adding leak sealers

 

[bengasman]

Leak sealers are a last resort solution.
You could of course loosen the nuts a bit, and screw the tail in another turn.
Failing that, you will have to take it out and do it again.

 

[gassafeman]

Turn off rad valves

Drain rad.
Re-do the tail with ptfe and LSX
Refill rad and have no annoying leaks. An hour or so out of your life!

As a plumber I do get the odd annoying leak, but the thing to remember here is.... would I leave a leak? Of course not. You have carried out some plumbing work and should be proud that it doesnt leak rather that embrace a slap dash approach.

You will feel so much better if you know it does not leak atall!

Paul

 

[dextrous]

Agree with taking it apart. Since I started using a bit of boss white smeared onto the PTFE (use gas PTFE - it's much better!) I've never had a leaking rad yet. Everything else leaks, obviously, but not the rads

 

[gassafeman]

Gas PTFE is the muts nuts dex! I thought Id be lambasted to advising its use with water.

This is no boast, but in 15 years, Ive had 1 rad tail leak, and that was me rushing with a dwindling role of PTFE. My 14 year old lad Ive now trusted with every rad valve change and hasnt had a leak yet. That is because he uses gas PTFE and LSX. Oh, and on his construction course he has been told he is doing it incorrectly!

I suppose, after 15 years I must be teaching him badly!

Paul

 

[dextrous]

Personally I don't like LSX because it smells Course I went on advised jointing compound with either ptfe or hemp.

 

[J Holland]

Sorry to drag up an old thread, but it seemed easier than starting a new thread on exactly the same topic.

I'm a DIY-er, and have drained/removed/re-installed 4 radiators in my house when we had rooms re-plastered. They were all fine with just PTFE on re-used tails. The latest one is causing me troubles however.

I removed the old radiator and took out the tails. I bought a new larger radiator, and installed the old tails using a few rounds of PTFE. The tails both leaked slowly. I drained the radiator and re-installed the tails with double the amount of PTFE, which fixed tail leak at the lockshield en,d but not the tail leak at the control valve end. I drained again and re-installed both tails with lots of PTFE and also smeared LS-X on top of the PTFE (after reading this thread). The tail at the control valve end still leaks, though agonisingly slow (a few ml over 24 hours caught int he bowl underneath the leak).

Do I need new tails? Is there a problem with the screw thread area of the new radiator? Is there anything else apart from PTFE and LS-X I should be using?

Many thanks in advance!

 

[Dan Robinson]

Loctite 55

 

[Hike]

Loctite 55 would indeed be a good place to start. Alternatively you could try taking a length of PTFE tape and rolling it up so it becomes like a piece of string, and wrapping that around the threads. This would give more 'bite'.

 

[J Holland]

Thanks Dan/Hike for the very quick responses! I'll try Loctite 55 and/or rolled up PTFE and report back

 

[Nige F]

Thanks Dan/Hike for the very quick responses! I'll try Loctite 55 and/or rolled up PTFE and report back

And then use a strand of hemp + about 2cc of jointing paste

 

[rarara]

could a cheap radiator be an issue too? recently on a lot of the plumbing supplies i have installed at home i reckon the machining quality is shoddy (probably some crap chinese made rubbish) judging by the amount of 'extra 1/4 turn' x10 or 'dismantle and cover in ptfe' i have needed to do

 

[Nige F]

You could be right rara. Plus BSP threads are very coarse that's why hemp+ paste was used - then the H+S police said germs could breed on it and stopped it's use on wholesome water pipes.