Radiator tail fixed extension leaking

[mrg481]

I have a common issue where the new radiator isn't quite the same width as the old one. Have got hold of some 30mm extension pieces and fited them but they leek. I have attached a picture for reference.

So firstly I removed the existing radiator tail. I then wound some PTFE tape around the 'male' end thread of the extension piece and screwed it into the rad. I then wound some PTFE tape around the male thread on the existing radiator tail and screwed it into the extension piece. I then connected this assembly to the TRV one end and the radiator valve at the other by way of the compression fittings.

The leak is coming from the following areas: Between the radiator and the extension piece and the extension and the exisiting tail..... A fast steady drip would best describe the leak. The connection between the TRV and radiator valve are both sound so the issue is clearly iwth th eextension pieces. You will see from the picture there is no rubber gasket present on the extension piece. That is how it was sold and supplied but not sure if there should be a gasket.

So what am I doing wrong and what other than PTFE tape should I be using? Also I wound the PTFE tape round about 5 times, was that not enough?

 

[acecharly]

When you wound the ptfe on, how many times did you go round? and did you put on the right way running the tape against the thread. As a rule I always go round 18 times

 

[acecharly]

Ahhh just re-read missed the 5 turns with the tape ....you need 18 turns.

 

[mrg481]

Many thanks for the reply.

Ah, that could be the problem. Only wound about 5 times round as I thought that would be enough. Def wound the tape against the thread though. So other than not enough PTFE tape there is nothing obvious missing?

 

[acecharly]

No mate its as simple as that 😉

 

[Simon F]

Hello MRG,
unless the fitting is cracked or damaged in some way then the problem is with the lack of thread tape.
the thread will be the same 1/2" but some thread do seem slightly tighter or looser than others.
have another try and remember thread tape is only 10-20 pence a roll, use plenty.

 

[stevetheplumber]

and a smear of bosswhite for good luck

 

[TBServices]

I use 12-13 wraps usually, although it often depends on the quality/size of fittings. Too much ptfe on a thread can lead to it being stripped/bunching up rather than staying on the threads.

 

[Mike Jackson]

I used to use 7 wraps and had no problems but I now use loctite 577 or loctite 55.

 

[PlumbBobBob]

i used one of those just today. as has been said plenty of ptfe and you will be fine.

 

[SimonG]

12 to 13 wraps and a smear of paste. (there's that word again, smear)

 

[TBServices]

I used to use 7 wraps and had no problems but I now use loctite 577 or loctite 55.

Gonna give this a try

 

[Phil]

I don't bother with these silly extensions anymore, just 15mm chrome pipe and a chrome compression 15mm x 1/2 male iron into the rad. Make sure valves are the 15mm comp type. Looks alot better and way cheaper.