Leaking towel radiator

[plumb_know]

Went to a job where customer has had new towel rad and new rad valves fitted, had leak coming from rad tail where it goes into radiator. Customer had bought new rad valve and wanted me to fit them as original plumber away. I thought when rad was fitted maybe they hadn't put tape round thread, so fitted new rad valve and rad tail using loctite and small amount of ls-x. This didn't solve the problem so I believe it must be a faulty radiator, would you guys agree with this?? Also when I was screwing in the radiator tail I could screw it all the way into the radiator, there was not a point where it would stop or become really tight, is this normal as I have never been able to do this on any other radiators??

All replies appreciated

 

[PlumbBobBob]

i would have used ptfe instead of lsx, around 15 turns then you wouldn't get any leaks

 

[SimonG]

PTFE and paste, plenty of ptfe as steveb said.

 

[plumb_know]

Previous plumber used ptfe though and it still leaked, I used to use ptfe but was advised to use loctite as apparently it is better ? What about the tail being able to screw all the way into radiator without stopping? It this normal? It didn't seem to get tight using loctite or ptfe?

 

[Paulplumb]

i would have used ptfe instead of lsx, around 15 turns then you wouldn't get any leaks

:iagree:

unlikely to be a faulty rad

 

[1967skyblue]

Previous plumber used ptfe though and it still leaked, I used to use ptfe but was advised to use loctite as apparently it is better ? What about the tail being able to screw all the way into radiator without stopping? It this normal? It didn't seem to get tight using loctite or ptfe?

yes this can happen i have noticed this on some tvrs as well,
just follow the same advice as what others have said, however take notice on how far you first inserted the valve then just dont insert it as far next time. i usualy get to the last thread or two then stop, with no leaks

 

[plumb_know]

So it's ok that I can screw the rad tail all the way into radiator? Only thing I can't work out is why it is only the one rad tail that is leaking? The other one is fine! Surely both would be leaking as both installed the same?

 

[erpkid]

So it's ok that I can screw the rad tail all the way into radiator? Only thing I can't work out is why it is only the one rad tail that is leaking? The other one is fine! Surely both would be leaking as both installed the same?

Could be one slightly oversized female thread but a generous dose of ptfe will solve.

 

[plumb_know]

Ok cheers for replies I will try with ptfe and some paste and see what happens

 

[stevetheplumber]

depending on what valves, your using if they a 3/4 unions try and find some stella rad valves with the rubber seals on the tails they are similar to the air vent and plug sealing method
if the valves are 1/2inch nut and ring type then its lots of tape and boss white im afraid

 

[Keefy]

Correct me if I'm wrong but aren't new radiators pressure tested before they leave the factory?

Our highly automated, high speed manufacturing lines feature pressure testing to 10.5 bar to assure weld integrity and a thorough leak testing regime, followed by a four stage inspection process.

^ From Stelrad's website.

 

[erpkid]

Correct me if I'm wrong but aren't new radiators pressure tested before they leave the factory?


^ From Stelrad's website.

I suppose it depends on how they are tested. If the test rig is set up like the old engine compression testers with a rubber conical adapter then an oversize thread would pass as the seal could still be made and the radiator body withstand the test pressure.

 

[IND_Nick]

I have noticed on some rad valves the lock shield tail thread doesn't go tight. If you have another set of valves try the tail for the TRV as they seem to fit better, plus as previously said lots of PTFE. ( found this with Plumb centre Bulldog valves).