Leaking Radiator/Valve

[HermsB]

Hope someone can help or give advise.

I replaced 3 radiators with new valves. I now have the following problem:

First, we refilled and bleeded the central heating system all was OK (no leaks). We turned the boiler back on, all the radiators heated up, still no leaks. We then turned the central heating system off to cool down and then we noticed that we had small tear drops where the valve is connected into the radiator. We heated the system up again, whipped away the teardrops and all is OK (no teardrops). Cooled it down and we have the teardrops again.

Also need to say that the teardrops are at all 6 valves of the radiator. We also tightened it as mush as possible.

Can anyone give some advise please. We did put some PTFE tape around the tread before connecting the valves (2/3 turns of tape).

Thanks

 

[tomy]

not enough ptfe , I usually put 10 to 15 wraps depending how thick the ptfe is

 

[RigidRaider]

I don't think 2 or 3 turns is enough. You should have gone on wrapping until you thought there was far too much there - it's amazing how PTFE compresses down.

Have you tried re-tightening the fittings to "F*** off" tight?

 

[HermsB]

Cheers RigidRaider & tomy


Yes RigidRaider, I have re-tightening the fittings to "F*** off" tight and then one more turn as well. Still the teardrop leaks.

I think you chaps are correct with not enougth PTFE tape, I was a bit to carefull with putting on to much.

I will redo the work and make sure I put on some more PTFE tape.

Cheers.

 

[Agile]

It all depends on the type of radiator and valve. Some seem to cut the thread too deeply. These need 10-11 turns of PTFE tape.

Another point is that the PTFE must be wrapped in the correct direction! Thats sometimes overlooked by DIYers!

Tony Glazier

 

[HermsB]

Agile

The thread on the radiator is quite a rought thread. The radiators are a classick style from Homebase and the valves are from B&Q.

I must say, I did remember that you need to turn the PTFE tape in the opposite direction on the thread as what you will screw it in.

It sounds like I made the mistake of not putting on enough PTFE tape.

Cheers