Help! Can't stop radiator leaking

[Jezzer]

Hi folks

I've ripped and replaced our central heating recently, bar the boiler, mainly fitting Kudox radiators from Screwfix, which are well reviewed. I'd taken advantage of the bundled TRV deal too - mainly Drayton. I've found that 4-5 of the 11 radiators I've fitted have leaked from around one or both of the tails, despite the usual 6 or so clockwise wraps of PTFE tape. I don't know if it's poor manufacturing (ie. the threads on the tails or inside the radiator aren't very accurate) or what. I've managed to fix all of these bar one, with extra PTFE tape and sometimes a bit of jointing compound. In one case, I noticed that the threads on the tail had tiny notches travelling along the length of the tail so I replaced the tail with one that didn't and that seemed to fix the issue, although I did add more PTFE tape and jointing compound, which could have been the fix.

One tail however just keeps on dripping. Any suggestions/tips on an alternative approach?

Cheers
Jez

 

[ShaunCorbs]

More ptfe it’s recommend around 15 wraps of pfte tape for a 1/2 thread

If that fails try loctite 577 or 55

 

[Darren Jackson]

Never had a problem with Kudox from screwfix they are a good reliable radiator and a good price with the TRV's thrown in. Just make sure you wrap 15 times for 1/2" and make sure you wrap the PTFE clockwise or else it will unravel and leak!

 

[snowhead]

I usually stop counting at 12 wraps of ptfe, but put at least 2 more on.

The first wrap I've always rolled the ptfe into a string and wrapped it into the base of the thread, but that comes from being commercial and mainly working with larger threads.

 

[ballvalve]

Paste and hemp old school. (You young ones have it to soft.)

 

[townfanjon]

I dont process any ptfe tape once you use loctite 55 you never go back .

 

[WC1]

I noticed the scoring on tail threads recently (can't remember make) it was as if they'd been ready roughed up to accept LT55...
Went over to LT 55 this year after advice on the forum and haven't looked back.

 

[centralheatking]

Hi folks

I've ripped and replaced our central heating recently, bar the boiler, mainly fitting Kudox radiators from Screwfix, which are well reviewed. I'd taken advantage of the bundled TRV deal too - mainly Drayton. I've found that 4-5 of the 11 radiators I've fitted have leaked from around one or both of the tails, despite the usual 6 or so clockwise wraps of PTFE tape. I don't know if it's poor manufacturing (ie. the threads on the tails or inside the radiator aren't very accurate) or what. I've managed to fix all of these bar one, with extra PTFE tape and sometimes a bit of jointing compound. In one case, I noticed that the threads on the tail had tiny notches travelling along the length of the tail so I replaced the tail with one that didn't and that seemed to fix the issue, although I did add more PTFE tape and jointing compound, which could have been the fix.

One tail however just keeps on dripping. Any suggestions/tips on an alternative approach?

Cheers
Jez

Jezzer, using PTFE tape ....is fine ...but you must counter wrap it so it tightens up as you wind the tail into the radiator stabbing...Then after 10 or so turns you then 'rope' the ptfe
ie... twist it and then finish with a couple of flat wraps. Many stabbings for rads are tapered threads and need this method. If they are straight threads then its easier less ptfe or use splodge as others above suggest...centralheatking

 

[OffshoreGas]

Radiator tails use parallel threads, parallel threads aren’t designed to seal with thread tape. You need an anaerobic thread sealant like Loctite 577. The thread sealant needs to be allows to cure before you pressurise the system, you can get an activator to speed this up.

 

[WC1]

Ready scored tails? on Drayton

 

[OffshoreGas]

Ready scored tails? on Drayton

Will seal fine with some thread sealant.
[automerge]1570130550[/automerge]

Ready scored tails? on Drayton

I think those notches are deliberate to retain the thread tape/clean female thread.