Tiny radiator leak... fixed itself??

[redmamoth]

I've replaced an old Type 22 double panel radiator in our living room with a nice 2 column oxford one, I managed to find one with matching centres so didn't have to mess with any pipework.

When I first filled it up and checked for leaks there was tiny bead of water right where the valve insert goes into the brush on the return side. Annoying as I did 4 wraps of PTFE and made sure it was nice and tight with the radiator spanner. Alas, I thought, I'll drain it tomorrow and re-seal the insert. So I come down this morning and there is no leak, it's dry as bone... I turned the heating on just to check, radiator gets nice and hot which it does. No leak, dry as a bone around that insert.

Could the PTFE have expanded and formed a better seal? Was it the fast flow of water when filling the radiator causing the leak? Should I just leave it now, or am I just delaying the inevitable here?

 

[JohnD]

Small leaks can clog with limescale

Please show some photos

 

[redmamoth]

 

[redmamoth]

Image above, you can see a tiny bit of rust has formed where the droplet was, maybe this has 'sealed' it...

 

[ianmcd]

Why on earth did you put PTFE on that part of the valve ???? you dont put PTFE on there, get some LSX or jointing paste make sure bothe faces are clean then a small smear of LSX or paste and do it up

 

[redmamoth]

Why on earth did you put PTFE on that part of the valve ???? you dont put PTFE on there, get some LSX or jointing paste make sure bothe faces are clean then a small smear of LSX or paste and do it up

Does it do any harm to have PTFE on there?

 

[Madrab]

Yes, it has probably rusted up and sealed. If you were using normal PTFE tape then you'd normally use 10-15 wraps, not 4. I use 6 wraps but that's gas tape which is thicker.

As suggested, those faces would be cleaned up with some 240grit or a sourer/scotch pad then ensure they are square on before tightening, shouldn't really need anything in that type of union coupler but a bit of paste if it won't seal.

 

[redmamoth]

Ok, sounds like it's best for me to drain the rad and re-do these valves. Just ordered some LS-X which should hopefully arrive tomorrow.

 

[ianmcd]

Ok, sounds like it's best for me to drain the rad and re-do these valves. Just ordered some LS-X which should hopefully arrive tomorrow.

remember just needs a very tiny smear don use too much it looks horrible

 

[Madrab]

This is just a case of using old over new fittings. When using old union fittings then the mating faces become pitted/marked over time and unless they are going back exactly where they were before then sometimes they don't seal properly hence why they should be cleaned before refitting. The paste will fill in any of those imperfections, promoting a good long term seal.